Hey there, I've compiled a complete line up of suggestions for changing the important stuff. The fluid are in parenthesis and they are the fluids the general consus came to (synthetic). I've basically cut and pasted old posts and grammatically edited some of their english. Let me know if I should update it!
Tranny change (Redline AutoTrannyFluid Synthetic D4): Take out all the bolts holding the transmission pan on and very carefully (because you are probably going to spill some automatic transmission fluid everywhere) remove the pan. Grab your new tranny filter kit, pop the old filter off and put the new one on. I dont know about your tranny filter but mine didnt have any fasteners... just gotta yank on it and it comes off. Scrape the old pan gasket off and clean the pan with brake cleaning fluid and then compressed air or lint free cloths. Put the new pan gasket on and bolt it all back up good and snug. Add 3.5 or so quarts to the tranny before start up then let it run for a bit and while holding the brakes shift through P,R,N,OD,D,2,1 holding it in each gear for 30-45 seconds... Check the fluid levels with the trans dipstick under the hood and look for leaks!
Rear diff (Valvoline GL-5 certified Synthetic 80w-95): You can do it 2 ways. 1ST WAY: Pull out the check/fill plug. next, pop the diff cover off (10 bolts) and let the fluid drain out. Then you have to scrape the old gasket off using a gasket knife. You can use brake cleaner and lint free cloths to make sure your gasket areas are spotless. Then install new gasket (silicone RTV sealant) on the cover and bolt it back up. Then add your gear oil in the check/fill hole untill fluid starts coming out. The level of the check hole is exactly how much fluid you need to add. 2ND WAY: You can also use some kind of sucking device to suck the old fluid out through the fill hole and then siphon the new fluid back in. You will need an additive if you have limited slip differentials. Look for leaks!
Front diff (Valvoline GL-5 certified Synthetic 80w-95): There is no cover that can be removed to aid this process, but there are 2 plugs to draw from. Take out the fill plug first! Then remove the drain plug. Let it drain and then put the drain plug back in. Add fluid until it starts coming out of the fill hole and then put the fill plug back in. Look for leaks!
Transfer case (Redline ATF Synthetic D4): The same fluid your tranny uses! There are 2 plugs; one for draining and one for filling. They are big plugs. Pull the fill one first and then pull the drain plug. Let it drain nice and good. If you want to you can add some extra to the fill hole to flush it a bit. Put the drain plug in, fill it up, and put the fill plug in. The fill hole is full level. Look for leaks!