Make sure it is really the cork gasket, and not the expansion plug under it, or something higher up leaking, been a few people that replaced it needlessly.
If it is really the cork gasket, just disconnect the necessary things and roll the rear assembly out on a floor jack.
Then tip it up on, so it is setting on the rear cover (wood blocks work nice) remove the attaching bolts, then the hydro assy lifts off.
Clean things, replace the gasket and reverse the order of dissambly.
You will loose a bit of oil out of the hydro when you lift it off the differential casting,
but if you quickly do that, and set it up, the leakage will be minimial.
First time it might take 1/2 a day, second time maybe an hour.
