Do what you feel is right and still be nice to her.
Just because you're breaking up doesn't mean you have to strain your relationship, go with her from time to time and see what she, and you, feel about it. It's okay if it doesn't work out however, you can become friends at least, severing connection with her is the last thing you want.
If you truly love her go for whatever you want to do. If she doesn't have any intentions of getting back together I would probably try avoiding her. I'm not an expert but a girl I really like promised to bang. She left my school and is currently working so I don't have many opportunities to meet her, so I cope with my feelings and forget her in the time periods I don't see her. I have dwelled really deep in to breakdancing so it is pretty easy to not think about her. But when I happen to meet her I feel happy and when we say goodbye I feel like shit as I remember the reasons why we might never get together. I usually stop caring after a week because I have a lot to do. I dunno, man. Feelings change so do whatever you think is the best and make sure you wouldn't look back and have any regrets about it. I don't have much experience so don't take my word for granted. Best of luck, Dog. <3