The "how" can vary from person to person. It took me years to get to a place where even now I can still have rough times. But can also turn to what works best for me such as CBT, ACT (can read up on these approaches on the web), reading and posting here, various exercise, journaling, daily meditation.
A therapist may be advisable at the start and it could even be light meds depending on severity. Perhaps this can be a start of self discovery, self understanding, and gradual change. It is an ongoing process that can be interesting and enjoyable. Hope this helps some.