I guess the trick is to catch them when they're not home, do they ever leave? Is there a way you can make them leave for a day if they normally arn't gone at same time? Even if it involves you spending money (ex: telling them to go on a trip to Wonderland or something and paying it) it will be worth it in the end.
Basically you want to do this in one quick swoop where they show up and you're gone and all your stuff is gone, with a letter saying that they need to either vacate or take over the lease because you canceled it and that they need to talk to land lord not you. I don't know how this works legally, you'll want to get your ducks in a row, check with a lawyer to make sure you can actually do this, but assuming you're the only lease holder I can't see why not.