In my opinion, before doing anything for her, you should first correct the mistake or cause of your break up in the first instance and if it were your fault, apologize and change accordingly. Show her that you still care about her and make sure she notices the positive change in you. Make calls to her and talk about something that used to interest her, respect her opinions, be supportive and first win her friendship then from there it could work out automatically and she would want to get back to you.
tell her how much you love her and how much she really means to you. it may take her awhile to answer but keep trying and tell her you love her if and only if you mean it. dont say it if you dont. good luck. hope it works out for ya