Before I go about fixing the world, I must first try a little self-improvement. Many people walk through life without really considering who they are and fewer still ask themselves if that is who they want to be. In my experience this is because most folks can't see how to go about changing themselves and some even think that this is somehow a betrayal of their essence.
To reinvent yourself you need three things. A vision of who you want to be. You need to know how to make a change in yourself and finally you need to have the courage to do it.
Your vision can be reached through many paths. Look at those things that you take pride in about yourself and contrast them with those things that embarrass you. This should start to indicate where your soul is trying to head. Next flesh out the ultimate form that you would take if you followed this path.
And now you have your vision. But don't think this will remain constant throughout your life. As you change, grow and learn you will want to alter your vision. This is a good and normal thing, so fear not.
The method that I have found to change myself is simplicity itself. Become an actor. Take one part of yourself at a time and start acting as if you had already achieved that modification. It will feel awkward and false at first but the more you practice it, including the feelings behind the actions, the more it will become natural to you. Eventually you will be acting correctly without even thinking about it and your motivation will become a part of who you are. Then you are ready to tackle the next part of yourself that needs improvement.
You will need courage...