Saurabh is right, I think it's time to sell this place. If you absolutely must keep it, make the tenant a cash offer ($500 is a good starting point) to leave, and pay them after all their stuff is moved out.
Money talks, hopefully your B.S. tenant will walk. Pay them, it's worth it.
If you get a lawyer, be prepared to give them $5000 in legal fees on top of the cash settlement you would have paid to the roach tenant anyway. Lawyers are an expensive waste 95% of the time.