I have a few suggestions if you want to win your ex-girlfriend back. It is up to you to choose which are most relevant.
- Be romantic. Show her you love her.
- Be different. Prove to her you've changed your attitude towards her and won't take her for granted.
- Be faithful. Don't chase other girls or ignore her. She needs to know you value her presence in your life.
- Apologize. Something went wrong the last time, and you need to identify what that was and demonstrate you won't make the same mistakes.
- Be prepared to give her space and to move on if she's still not interested after you've tried your best to win her back.
Just because you want to renew your relationship doesn't mean she does. Sometimes you can win a girl back, but sometimes you have to accept a relationship is over. People grow apart, trust gets lost, and it might never be the way it was. But the earth keeps turning and broken hearts heal so don't get depressed if it doesn't come together the way you're hoping. Try your best and see what happens.