Write an article based on this "Ignore your guest(s). Do something they don't like. Entertain someone else. Tell them to leave."
Stop being social, and give them as cold a shoulder as you can. This is definitely a last resort, as it meets rudeness with rudeness, but some guests are so dense as to never take a hint. When your guest begins to feel more like the cable guy and less an invited guest, the door will be all the more appealing. Don't leave them happy, though. Plenty of terrible guests would be thrilled to sit watching your big TV in silence. Act as though the TV is "out of order," and tell them that they're on their own for dinner. Stop being a host, and start being a roommate. Forget boring, if you know your overstaying guest well enough, do whatever bugs them. Play obnoxious music, insist on reciting Elizabethan poetry, keep the channel locked on C-SPANwhatever you have to do. House guests who overstay do so because, for whatever effort it would take to leave, they'd rather stay where they are. Turn that reasoning on its head, and your guest will be out the door in moments. If you haven't a good friend there to move your guest to the door, invite one over. Then, pay exclusive attention to them. Make the overstay-er feel as though they're intruding on an intimate meeting of good friends. This, hopefully, will reveal the guest's impoliteness more clearly and have them apologizing all the way to the door. For guests who stay several nights, pretend this good friend has come to take the room they had been using. Make this appear to be a long-standing invitation, so the overstay-er has no choice but to find new room and board. This is the ultimate last resort, and there's not much to it. For the guest for whom none of the above had any effect, there is nothing else to do than to tell them, directly: "You need to leave." By this point, don't ask them to leavetell them. Do as bars do: shut off the lights, hang up the chairs. Make it unthinkable to stay any longer.