ive done it. you will need a press to pop out the crank. you can usualy get one side off by tapping, then press the crank out the other side with a arbour press. if the bearings are still in the cases instead of stuck to the crank, then you gota press them out too. only tool you would need is a crank puller/installer tool. i didnt use it, but ive got mad skillz
no but seriously get the tool. that was such a pain in the ass to use that sh*t. what i did was like you see, some spreaders to sit on the edge then i used washers as spacers and i just tightened the bolt on the crank, loosened, more spacers, tightened and repeat. you gota be careful about clearences, like how far you pull the crank in, the gaps are small and precise.
other than the crank, its easy. just dont let your transmision fall out, leave it in 1 side of the case halfs or its a pain in the ass to get back in right. also, to keep the clutch from moving, jam a penny(or any soft metal thing)between the gear on the crank and the gear on the counter ballencer(like above the clutch behind it) that will hold for most gears and then to get the nut off the inner clutch part, put it in gear and put some vice grips on the sproket shaft and let it sit against the case or hold it.
if you have an impact gun, makes everything so much easier. a impact screwdriver is also your friend for alot of the case screws.