[larryn]

A diff has an input flange that connects to the drive shaft, and two output flanges that connect to the two half shafts.

If you have the diff sitting there, the output flanges pop right out with very mild prying. If you yanked on them, they would probably pop out, but use a screwdriver, since it is easier. Once you pop one out, you'll see how easy they are to replace.

The new output flanges will slide right in the same hole that the old ones came out of.