Yes. Traditionally, this is called CBT, or cognitive behavioral therapy. It's effectively therapy to slowly reprogram you for some desired behavioral outcome. It's a very slow process, since our wetware is not like computer hardware. The process of completely changing yourself can take several years through consistent behavioral modification that restructures most of your neural networks. There are certain programs that facilitate this sort of change. The army, for example, breaks your character and will down in order to reshape you and mold you into what they desire: a rigid and obedient authoritarian servant who unquestionably obeys orders and respects the chain of command.
To do this on your own using a custom-tailored program is very challenging. It's one thing to want to change. It's entirely another thing to know what to change into and how to do it incrementally and methodically. Rumor has it that there are all sorts of various top secret programs that have been designed to change people into becoming certain other people. By far the best way to program a mind is to do it when they're young children. It's a very slow process for adults, but it is technically possible. For you, that's obviously not an option since that window has long been closed.
The best thing for you to do in this regard is to pick one very specific, minor thing you want to change about yourself and slowly take steps to retrain your brain for that. And then from there make tangential changes.
What is it that you want to change exactly? Don't say "everything," be specific.
