Psychiatrist Ivor Browne says: instead of a way of avoiding external danger, it [dissociation] is now utilised to deal with the threat of internal stabilisation; whenever we are faced with an overwhelming experience that we sense as potentially disintegrating, we have the ability to suspend it and "freeze" it in an unassimilated, inchoate form and maintain it in that state indefinitely, or for as long as necessary.
There are many different ways to help us do this, safely and gently. What is key, as Bruce Perry says, is a bottom up approach, in line with our neuroanatomy. In order to change a neural network he says, you have to activate that neural network. So in order to change our stress response, we have to activate it through somatosensory routes, i.e., running, breathing, walking, chanting, visuals, rhythm and so on. As Peter Levine says, this is like walking a tightrope, too little activation and nothing changes, too much and overwhelm results (which keeps the trauma loop going), just enough activation is the goal so we can make much needed changes.