Dave, from memory you use one of the engine mounting bolts. See if you can find one that screws into the thread of the rotor which will be bigger than the thread in the end of the crank. Once you have it screwed in and have a bit of weight on it give the head of the bolt a sharp hit with a copper hammer and it should pop off. If it's tight just leave it with weight on it and give it a hit every time you walk past it - it'll come off eventually,
Pete.
