By actually going there. So not only think about Human Design and your chart and all its details (while also important), not just contemplate the information and its implications (while also important), not just study Human Design (which for some is quite important), but by actually going there, by trying to live it, by making mistakes, by experimenting and experiencing, by comparing your experiences with the theory and other peoples stories. By learning to not only understand but having the experience, of which energy is yours and which is not yours through Transit Cycle tracking and journaling. Deconditioning is something we do.
And if you need support in doing so, find that support.
The how question is one of mind, but mind can not solve it, not ahead of experiencing at least. It is not within the capacities of mind to ever solve it. We factually need to go and experience it, ourselves. We can talk about what it was like doing so, with others, but hearing what it was like, for others, does not decondition -you-.
You simply have to experience it yourself.