I changed the oil in the differential and transmission a couple of weeks ago. It was pretty straight forward. Drove the car for a 20 minute run. Up on the ramps, jack up the rear end, lower it onto jack stands, and crawl under. The worst part was trying to get the oil into the filler holes. I borrowed a filler hose from a co-worker, but it was quite the task getting the oil into the cases when the bottles were nearing empty. If they only made like a 1 liter industrial syringe. You could inject the oil right into the case! The real awful part was that it was 98 degrees (F) out and there was 100% humidity while I was laying on the hot asphalt driveway. Musta lost a few pounds of sweat that day.

I was amazed at the gunk (metal filings?) and metal pieces (1mm or so) that were on the magnetic drain plugs!



On the plus side, it does seem to shift better and makes less whine when I'm driving along now. I could only have put in more 85w-90 than I took out, I'm hoping anyway. Also had to buy the correct sockets to do the job. Once again I found that info here on the bb! Couldn't track down a 12mm hex socket, as soon or as cheap as desired, so I bought a 12mm hex wrench from Sears. Used an improvised breaker bar and that did the trick getting the filler plugs off.
Good Luck!