All the 'guts' come out the back, after removing the large diameter sheet metal plate held on with six countersunk flat head screws. So you will need to pop the flywheel off the crankshaft taper.
The large nut you are turning threads in or out to vary the compression on the six clutch springs. The stud that it is threaded on is not the end of the crankshaft, but part of the crankshaft nut. If you remove the bit you are turning, you will see the hex for the crankshaft nut down in the recess of the flywheel hub.
-Doug