Originally Posted by starrywhite

My most effective tool was to find a 14mm size bolt with a lip, of the kind that are strewn all over the ground at wrecking yards.

Drill a hole for the bolt into the side of one end of a heavy block of wood that is about a metre long. Screw it in leaving about 15mm of the bolt protruding, enough room for the lip to grab on the inside edge of the seal while the block rests against the diff.

Apply the bolt lip to the seal and give the other end of the block a good kick and your seal will fly out. You'll spend about a minute giggling.