The clutch is threaded onto an axle with 2 symmetrical flats. If you look under the clutch with a flashlight and rotate the clutch slowly with your hand you can see the flats. You can use the flats to prevent the axle from rotating in order to unscrew the clutch, similar to how you would prevent a bolt head from rotating in order to remove a nut at the other end.
1)Make sure the blender is unplugged before attempting to do repairs.
2)Use a small wrench with the correct gap that is thin enough to fit between the clutch and the housing or a thin pair of needle-nose pliers to clasp the flats and prevent the axle from rotating.
3)Unscrew the clutch with a set of traditional pliers while preventing the axle from rotating.
4)Hold the axle stable as before and screw on your new clutch by hand until it seats firmly on the axle.
5) Write or e-mail Kitchenaid and complain about this flaw. If you are lucky they might send you a couple of clutches for free. I would guess it is worth the try.
Mike
April 2005