Great question. Training your brain to act differently takes time and repetition. An excellent starting point that I'd recommend from personal experience is the book, "The Greatest Salesman in the World" (Amazon: >1000 reviews, 83% 5 stars).
It presents important learnings in a format that is specifically structured to help you change how you think / act, all in an extremely positive way, not in a "stereotypical salesman" way. Each chapter is somewhat short, but they're meant to be read over and over for several days before continuing to the next chapter. This helps you actually change your brain and behavior (again, all in a very positive way).
Btw, I'm a neuroscientist, so I know a thing or two about how the brain learns. Let me know if you'd like to do a call for more specific advice related to your particular goals.
all the best,