Remove the three bolts holding the cases together and the two nuts fitted to the studs that locate the mag straps..
Next remove the timing gear and crankshaft pinion....
You will see that the pinion fits against a shoulder on the main shaft..
You will then need a piece of tube that is slightly smaller than the large diameter of the shaft and has a hole up the middle that just clears the shaft where the pinion fitted....It also needs to be a few inches longer than the piece of shaft the pinion was fitted on..
Slip the tube over the shaft, against the shoulder and apply a few blows with a mallet/hammer...This will usually get things moving...
Ideally, if you have access to a lathe, make the tube as thick as you can within the limits described and don't drill all the way through to leave a solid end to strike against...
Once the two halves are separated you can usually pull the crank from the drive side by hand...If not a few blows with a hide mallet on the end of the drive shaft will get it moving...Ian
email (option): ian@wright52.plus.com