Get evidence of marijuana use. A nanny cam is ideal. Smartphone video works but more tricky to be covert.
Go to management and request a room reassignment. If pressed, say you want a non-smoking room. If they refuse reassignment to a non-smoking room, say you don't want to make trouble... will they let you out of the lease, since they can't provide a non-smoking room? You don't have to say what your roommates are smoking and probably better if you don't.
If they deny both requests, the next step is to post the video on every social media you can access with comments that the apartment management condones drug use. Because it's true. Then maybe they will negotiate.
If it's university housing, so much the better.
