Replacement is easy:
(1) keep the axle tubes level with the road (there's a lot of fluid in there, so you don't want to re-fill the diff while the tubes are hanging down-- you'll over-fill!)
(2) open the fill bolt on the rear of the differential, using a large allen socket drive (I think 14mm or 17mm).
(3) open the drain bolt (same size allen bolt) underneath the diff and let the fluid drain out. (look for metal particles etc, to judge the health of the diff)
(4) close the drain bolt, and re-fill diff from the fill bolt hole. Do this until the fluid is level with the fill hole. Replace the fill bolt.
(5) while you're down there, check to make sure the breather tube (screwed-in above left side of diff. casing) is clear. There is a small felt pad trapped between the top of this metal tube and a metal cap. You can pry it apart and clean the pad and the metal parts.
I usually do this job while the car is parked on a level surface, without having to jack it up, but you may need to jack it up depending on your 'agility'. If you do jack up the car, make sure the axle tubes are horizontal.
Hope this helps.
WAQAS in Austin, Texas
