tricky problem.

first things first, collect all of the fine china in the house. while holding the gilded edge out, thumb pointed in and your face making a pout, bring china pieces down at a 45 degree angle, making direct contact with the door knob. this will loosen your door knob and make the next two steps that much easier.

eat a half dozen potato chips over the sink and allow the crumbs to fall into the garbage disposal. this will annoy your door knob and encourage it to give up it's karet energy. that is: energy it has stored within its many faceted, smoothly rounded face.

take a large, powerful drill and using a bit of at least 1" in diameter, make 3 holes around the door knob, as far apart as possible from one another.

grab a tiling trowel and biscuit mix (cornbread is my favorite), add water to biscuit mix (you can create this on the floor, use sawdust as flour) and insert into mouth DO NOT SWALLOW. with this mixture in your mouth, place your mouth on the door knob, teeth touching the metal portion. lift the tiling trowel over your head and bring it down with a firm motion onto the crown of your skull. you may lose a few teeth but the biscuit mixture is there for a reason. i've never swallowed a tooth while removing doorknobs this way. repeat until doorknob loosens.