^ You want to know how? You have to convince her that you've change already to a better person. I mean no more flirting and bad habits, etc. Buy her some flowers. Visit her more often. Ask her whether she had her lunch/diner already. Be as sweet as you can be for her. Treat her like a queen. But if those won't work, at least you did what you got to do. You've made effort and shared your time with her.