You can't. You can't have a " do over" in life. You can have a "do better" or a "do more " or any other " do's " you can think of. Learn from what you have done so you can improve and do better or do what you should have done. As you can see the emphasis is on "do". It should be "start now, not later". When you wake up in the morning it will always be today so do something about it today. No "over's".
I want a do-over! Do a road map. See what u want to change, and how u plan to that and start implementing.