Screw giving them notice! Tell them to start doing stuff now or their gone! Personally, for my well being, I would have put up with it for maybe a week and then told them the above. If they didn't listen, I'd put their stuff outside and tell them "Tough luck!" They aren't paying anything and they are not on the lease, goodbye! It sucks that you might lose a friend, but people lose friends every day.
Sanity is at stake here!
Sanity is at stake here!