The first thing that you have to understand is that there is absolutely NOTHING you can do to make someone do something they don’t want to do.
If you’ve had a disagreement with the other person, you can apologize – not necessarily say they’re right, but if you did something wrong, apologize for your actions. Or if you started the fight, say you’re sorry that you started the fight. Say you miss the person’s friendship. That’s about all you can do. Some relationship rifts mend with time. Some never do. Some were meant to end, and the circumstances become unavoidable.
Never pass up an opportunity to say something nice but true about the person to someone else. Gossip always gets back to the other person, good or bad.