Is he passing his exams?
If he is as bad is you're making out, then I doubt he'll change no matter what you do. You could smack the shit out of him, if only to make yourself feel better.. not only that, but going by what you said he deserves it.
I'm also bearing in mind there are two sides to every story, and i'm not calling you a lier here, but perhaps your perspective of things is a tad more dramatic than he sees it. Although you seem sure you want shot of this guy, in some cases mixing two different people can result in a positive experience.