What to do? What to do? Help?

Give them a 30 day notice, a legal one. It will still be hard for you to get them out if they are there longer than 30 days. I'd speak to a lawyer of the cops about the process and what if they are not out. I'd ask if you can shut off their lights, or something if they are there beyond 30 days. I'd ask if you can charge them rent suddenly and how to do it.