Well, fortunately, people around here know as little about the law as your average person, and I told them to vacate before I had the cops come and make them vacate.
Two things assisted this: all the drugs they were doing (mention of cops makes drug-people scarce) and the fact that I knew they were planning to leave yesterday anyway.
Since they left some of their stuff behind, I changed the locks so they could come and see me (for once) to get it... which, of course, I'd be happy to give over.

^ THIS is how the law SHOULD work. Not protecting scumbags, degenerates, and moochers - it should provide ample, speedy recourse for property owners and those serving their interests. For frame of reference, had they not blatantly lied to me (three times!) about paying rent that they never intended to (in other words, had I deduced that they truly intended to pay, but were in dire straits), I would have given them a whole week to leave. That, in my opinion, is the maximum that moochers (non-payers) should get to vacate someone's property. I am a very nice guy in every other situation, but lying and welshing on debts is deplorable and dishonorable... and deserves to be treated that way!