It will take a lot of patience from him and a lot work from you and it won't be easy. Dialectical behavior therapy has been known to be successful for changing the self destructive patterns. If you're anything like me, you will grow to hate the word mindfulness and the inventor of DBT, Marsha Linehan will become your mortal enemy due to her awful videos. :)
Anyhow, it can be done, but it won't be easy. However, it is 100% worth it in the end. Good luck!!