Just to add, you can also put some rope into one of the cylinders and bring that piston to TDC. It will jam solid to prevent the crank from turning.
Power: I would suggest getting a long 3/8" drive extension and, after removing the rear transmission support & driveshaft, reach up over the top or upper sides of the transmission to the top two bolts. Harbor Freight makes a set of 'wobbly' extensions. They are machined or stamped such that the square drive allows the socket to shift up to XX degrees from straight on. They are WONDERFUL for doing clutch jobs. You can snake the long extension up with a wobbly extension added, and the socket will most times just push right in place without any trouble at all. They also are a lot more usable than the 'universal joint' sockets because they won't break as easily.
FWIW, you can buy 'blind internal pullers' from HF, or you can pack the pilot bearing full of grease or similar, and then use a tool of appropriate diameter to 'hydraulically' push the pilot bearing out. A hammer comes in handy to operate the 'plunger'. Replace grease or oiled 'fluid' as needed. I read the other day that someone used oiled paper towels or something in lieu of grease. Brain cell must've died... can't remember what it was, but it made sense turning a dry substance that would fall out into one that would stay there, and wouldn't hurt anything. Just can't remember.
tom
tom