Breakup advice

My best friends boyfriend broke up with her about 6 months ago after 8 months of dating and a little over a year of knowing each other. She has been severely depressed ever since. She has moments of being happy and then she'll be sad again. She talks about him all the time and how bad she wants him back but the truth is, he's an asshole. He shows off other girls in front of her, he's an alcoholic, he'll sleep with her (after breaking up) and then yell at her to leave. They live down the hall from each other. So she can't really escape him which doesn't help with the moving on process. I just really want some advice on what to say to her that might really affect her in a positive way. Something that will at least help her see that life can be just as great without him. I have tried absolutely everything to help her and it's tiring because she just doesn't listen.