Hey dude,
I feel your pain...
Whats been given so far is good advice. To summarize:
Rear axle - Change the fluid. Begin by taking the axles out. Go ahead and look over the bearings on the ends of the shafts while you're at it. Then, remove the rear driveshaft and third member. Be careful, those third members are heavy. Most of the old oil will pee all over the place when you're pulling axles and the third member. However, you will need to clean the last bit out of the bottom of the housing with rags. Once this is done, put the third member and axles back in. Be sure to use plenty of RTV on all the sealing surfaces. Fill it back up with 90W gear oil. If you have a limited slip, make sure your oil has Limited slip additive.
T-Case - Change the fluid. Crawl under your Bronco and take a look at the back of your T-Case. There should be two plugs. Remove the upper then the lower one. Give this oil plenty of time to drain. Put the bottom plug back in, fill it up with the proper gear oil, and put the top plug back in.
Trannsmission - Check the fluid by pulling the dipstick and looking at the coloring. It should be consistent, dark red. If it looks pink or frothy, you need to change the fluid. This is also a good time to change your ATF (Auto Trannsmission Fluid) filter. Begin by removing most of the bolts from the tranny pan. This is a "kind of square" metal pan on the bottom of your tranny. I say most because you've got 7 qts of ATF waiting to dump on your head up there. Leave 4-5 bolts in one corner, and one or two in the oppisite corner. Place the drain pan under the pan, and loosen the two bolts in one corner. You might need to hit the pan with a hammer to break the seal. Use those two bolts to lower one side of the pan. This will drain a fair bit of fluid from the casing. Next, remove the rest of the bolts with one hand while holding the pan with the other. Once the bolts are free, use both hands to lower the pan (which will be full of fluid0 into a bucket, drain pan, etc. Once again, let the tranny drain throughly. Clean out the pan, install your new filter, and replace the pan. Again, seal it up good with RTV. Fill the transmission through the neck for the dipstick. Make sure the truck is warm and idleing in "Park" when you check the fluid level.
Crankcase - Just change your oil. Put a half quart of ATF in the crankcase (this will help clean it out), drive the truck a bit (unless there is ALOT of water in the oil), and drain the oil. Change the filter, remembering to fill the new filter with oil before you install it. You might need to change the oil several times to clear the water from it.
Finally, go ahead and check your power steering as well. if you change the fluid, be sure to use ATF instead of power steernig fluid if you have a Ford pump.
Grease everything. I'm not familiar with TTB, but you'll need to change the gear oil in it like you did the rear. Grease all your steering joints as well.
