You've recognized some actions and behaviors in your past that you dislike. Your next step should be to examine those things and try to understand why you did them. Do you have a selfish streak? Arrogance perhaps? Do some honest introspection and try to figure yourself out.
After that it becomes a matter of working to recognize those negative or unwanted behaviors so you can do what you can to avoid or alter them. Bettering yourself is a very long process, but eventually you might get to the point where you no longer have those unwanted thoughts or behaviors without needing to consciously manage them. If you do, congrats, issue successfully resolved. If not, it could be something you struggle with for the rest of your life.
That may sound like a huge pain in the ass, and it really is, but consider what you dislike about those things you've mentioned. Consider what kind of person you want to be, and how you want others to perceive you. Getting what you want often takes hard work, and that goes for personality things just as well as it does for material desires. All you can do is set out to be the best person you can be and try your hardest to stick to it. There will be bumps on the road, hard times that will make you revert to those unwanted actions, but that's fine, nobody is perfect. Just kick your own ass back onto to your desired path of self improvement when you can and all will be well.