Leaking Pinion Seal...8-3/4 ???

not bad, take of the drive shaft of course, then if the car is on the ground rear wheels, use a large breaker bar on th enut. it should be pretty tight, or a good impact zap the nut off, pull off the flange, pop out the seal.

I would put in a new crush sleave and torque to specs, some guys say to just mark and count the threads, just make sure that the backlash is ok. If you do not have a seal install tool a large socket works to for tapping in the seal evenely.