Pull out the spark plug and stuff a piece of rope into the cylinder. DO NOT push all the rope in, leave an end sticking out so you can remove the rope later. Now remove the side cover where the clutch is and remove the nut on the end of the shaft but BE CAREFUL, THIS IS A REVERSE THREAD NUT!!! The old saying of "Righty tighty, Lefty loosey" IS NOT TRUE HERE!! Since you have stuffed rope into the cylinder, the piston should be blocked and you should be able to remove the nut and pop off the clutch. Cheers!!
Fred Flintstone, November 2011