How to change the brain in order to change how one habitually thinks and feels? In this snippet from "You Are Not Your Brain: The 4-Step Solution for Changing Bad Habits, Ending Unhealthy Thinking, and Taking Control of Your Life" by Jeffrey Schwartz

Schwartz states that refocusing attention can actually change brain structure so that habitual ways of the brain are physically broken and other new healthy behaviors become habitual with new connections in the brain.

Are their any other studies along these lines that mention how to change how one thinks and feels habitually?
There's over 100 years of learning research and theorization now that pretty well establishes that yes, if your behaviour changes then your brain changes (and vice versa).  When you learned to tie your shoes your brain changed.  It quickly became a habit and you don't even think of it... can't even do it if you do.  When you learned to speak your brain changed.  When you had a child of your own and spent 6 weeks without regular sleep your brain changed.  It's hard to give you a specific reference for any of that.  The brain is what guides your behaviour.  If your behaviour is changing then your brain is changing.  Your brain changing is neither magical or surprising, that's how you learn.

That said, I've never seen the "habit" centre.

If you really want a reference start with this.

[Aside: It's kind of absurd that he talks about how you are not your brain but now you're going to change your brain to make a new you.]