What did the lawyers you talked to say about getting him out? They would be more versed on the laws of your state. Generally, if he is on the deed he has as much right to stay in the home as you. If he isn't on the deed, but uses your address as his, you could try going through the eviction process, but other than that, I know of no other way.
Chances are, if he refuses to leave, you would have to live with him unless you yourself leave.