This method is outlined in the book "A Theory and Treatment of Your Personality: a manual for change" by Gary A Flint. You can also learn about his method from watching his youtube channel titled "Gary A Flint".
Before you learned how to speak, your brain was busy gathering data from all five senses. In fact, your brain has been gathering data even while you were in utero! Eventually as you developed into a toddler, you learned how to use words. Your brain has associations between words and sensory data. These associations are called your subconscious. Your subconscious mind connects the associations in your brain (which are thoughts) with your muscle memories. The associations in your brain are thoughts that are stored as words. These associations allow you to think thoughts and put together sentences. Every word you speak has a vast collection of neurological muscle memory rooted to it. Therefore, you can think of your subconscious mind as a supercomputer language processor!
You may be wondering why, if you have such a large super-processor inside of you, you don't always act like a genius. The reason why, is your conscious mind only processes one thought at a time. Your subconscious is the part of you that delivers information to your conscious mind, when your conscious mind needs it. For example, right now, you probably are not thinking about the answer to the question I am about to pose, because you don't know what the question is! But if I were to ask you what your birthday is, the answer would be delivered into your conscious mind by your subconscious. It is your subconscious that pulls information out of your repository of body and thought associations for your conscious mind to enjoy and use as you need.
Sometimes in life, a trauma occurs. When this happens, the associations in your brain (your thoughts) are not properly linked with your muscle memories. Your body may be holding muscle memories for which the reasoning part of your brain is unaware.
This occurs because when the body is feeling overwhelmed with the emotion of fear. When this happens, your body stops sending energy to the forehead part of your brain (the prefrontal cortex), where you make thought-based decisions. Instead, your body sends its energy to your brain stem where you make muscle-memory decisions. Your brain stem controls functions such as breathing, heart beat, and the very basic muscle movements based upon their memory that you need to survive.
After a trauma occurs, you mostly only remember what happened to you before your prefrontal cortex shut down. The body memories and the sensory data of what happened during the trauma is stored in separate parts of the brain, and are linked at the brain stem which controls your muscle memories. By re-processing a trauma, you can restore associations between your thoughts and the muscle memory that were activated during that trauma. Doing this brings relief and helps you move through life more calmly, because you won't have to deal with as many sensory experiences that trigger a fight or flight response. This occurs when you have unprocessed trauma because re-exposure to sensory data that reminds you of a trauma activates the fight or flight response due to muscle memory stored in nervous system that your prefrontal cortex doesn't recognize.
For example, perhaps you were attacked by a thug who was wearing a certain type of deodorant. If you haven't fully processed this trauma you may have some amount of amnesia from the event tied to that particular smell. Then one day, you smell that deodorant while walking through the aisle of a grocery store. You start to feel nervous and uncomfortable, without knowing why. The reason why is because you were exposed to sensory data that your main personality is does not have chronological memory about. This data activates a fight or flight response, even though you are safe in the here and now. By processing your trauma, your brain will be able to correctly label the smell as linked to an event in the past, and the fight or flight response will no longer activate.
In order to process a trauma, you need to teach your subconscious a method where it can process traumas. But first, your subconscious needs to understand exactly what it is. Your subconscious is the compilation of associations between the memory stored in your brain, and the memory stored in your physical body. (You can think of the memory stored in your physical body as your unconscious mind).
Your subconscious is so powerful, that it can actively locate every trauma that you have ever had. Your subconscious is able to do this by tagging every time you feel a feeling of discomfort. Just by reading this, your subconscious mind is learning about itself and will able to start healing itself with the process-healing method.
But before you start healing your traumas, you must learn how to process your traumas slowly.
Let's say you learn the process-healing method and decide to process a trauma. As you begin to process this trauma, a certain amount of discomfort starts to become noticeable to your conscious mind. In other words, you are aware you are feeling discomfort. Let's label the threshold where you become aware you are feeling discomfort as 100 units of pain.
Now, with your conscious mind, make the decision that your subconscious will only process 5 units of pain at a time. (Repeat to yourself: if 100 units of pain feels noticeable; I will only process 5 units of pain at a time, resting in-between, until the pain is fully processed). By saying this phrase aloud with your intent backing it up, you are directing your subconscious on what to do.
After you have processed 5 units of pain, you will take a break from healing and re-cooperate until you feel fully restored and rested. You will allow yourself to feel complete relief and be fully restored before processing the next 5 units of pain. With this strategy, your subconscious mind can begin to process your traumas in the background while you function in your daily activities. A very small fraction of trauma should be processed at a time so as not to overwhelm you. After each small portion of trauma is processed, your subconscious is instructed to rest until you feel fully restored before processing the next 5 units of pain.
At this moment of time, if you by chance have any trauma parts activated in your awareness, you may have many fears and reasons why you are not ready to process a trauma. For example, you may be afraid of the visual memory of some of your traumas. You can instruct your subconscious to hide the visual memories but still treat the underlying emotions of the memories to help you feel safer. You may feel that healing a memory will cause you more pain in your life. Remember, the only reason why you would want to process a trauma, is so that you can have less pain in your life, and more satisfaction. If there are any parts of you that disagree with the healing process, they can join a stand by team and watch other parts get healed first. Then, if they choose, they also can be healed if and when they feel safe and ready. In this way, your trauma parts can join a trauma healing team. Your subconscious can tag each part that wants to be healed and put them in order of which needs to be healed first to which needs to be healed last.
Now we will explain the process-healing method. This method was developed when Gary A Flint was working on his clients using EFT (Emotional Freedom Tapping). This healing therapy is based on research called thought field therapy. This includes the idea that dissociated memories have a field around them with a positive or negative charge. By tapping on the body, in certain places; the memory field can change from a negative or positive polarity to a neutral polarity. This demonstrates that healing has occurred. Gary A Flint discovered that his clients had certain parts of the body that needed to be tapped in a certain order in order to heal certain traumas. One day, Gary A Flint had the idea to instruct the person's subconscious to internally tap on the nervous system on the parts of the body that needed it in order to heal the painful memory networks. He found that the subconscious was able to carry out this task very effectively, and thus heal clients from deep levels of trauma. He has now developed the process-healing method for others to use.
The subconscious mind, being the language processor that it is; learns through metaphors. Therefore, the process-healing method will be provided as a metaphor to help your subconscious mind tag each trauma association it has stored in a trauma memory bank, and then treat it with the provided healing metaphor based on his internal tapping technique and theory. When Gary A Flint uses the terminology "dissociative part;" he is talking about the fight or flight response that is activated in response to a triggering piece of sensory data. He calls these responses "dissociative parts" because they represent the memory banks of sensory data that are triggered that are disconnected from one's main awareness.
This is Gary A Flint's Process-Healing Metaphor:
Subconscious, imagine the brain is a soccer field, a smooth playing field with no bumps. When the phobia, negative belief, painful memory, or dissociative part becomes active and moves onto the playing field, gopher holes pop up in a particular sequence. [Gophers are animals that burrow underground and push to the surface, leaving mounds of dirt.] You can treat the emotion by remembering the sequence of gopher holes and gradually smoothing the dirt over each hole a little at a time with a feather in the remembered sequence, repeatedly, until the gopher holes disappear. 
Now that you have this metaphor, your subconscious can use it to treat and heal any phobia, trauma, or triggered neural experiences that you may have. If you find yourself experiencing discomfort, you can direct your subconscious to heal the underlying trauma using the process-healing metaphor. Some people are able to muscle test to know if the healing has occurred or not. If the healing has not occurred, it is because there is a barrier that is blocking the healing from occurring. There are many different barriers that can block the healing of a trauma. If one is experiencing a barrier to healing, one can troubleshoot what the barrier may be. Many times, the barrier is another fear that must be treated. For example, a part may be blocked from healing because it feels that healing would be painful, or make the memory worse. You can direct your subconscious to treat the fear that healing would be painful by explaining to yourself that healing will bring less pain and more satisfaction in your life. And that healing will be done slowly so that you are not overwhelmed with the process.
Gary A Flint has a list of possible barriers to healing in his book. Therefore, one can obtain a copy of the book for a thorough look at what some of these healing barriers may be and how to overcome them.
 Flint, Gary A "A Theory and Treatment for your Personality: a manual for change" NeoSolTerric Enterprises, Vernon, BC Canada email@example.com copyright 2006 p.97 Phone: 250 558-5077
Here is the video of Gary A Flint explaining the Process-Healing Treatment method. It is also recommended to watch the first 4 videos of this series.