Originally Posted by THE DOCTOR
Put a squirt of after run oil in the exhaust port and it will hydraulic lock the piston so it can't turn after you use the channel locks to break the nut loose.
To clarify for the original poster, this is the technique I use for reassembly if the clutch nut is all bugered up with Loctite and the crank still spins. Rotate the crank to get the piston to TDC, fill combustion chamber with after run oil, reinstall glow plug, tighten clutch nut only to where it is snug. After that, you can emty the oil and use channel locks or a clutch tool as pictured to tighten firmly.
For disassembly, just use channel locks or the clutch tool shown and it should come off easily. To break the flywheel free, just rap the back side of the flywheel with a hard piece of plastic like a screwdriver handle and it should pop right off of the collet.