Just changed my front and rear differential oil which wasn't that much of a problem to do. Now I am thinking about changing my Transfer case and transmission fluids but I am not sure how difficult it is to do.
Does the transfer case change out like the rear diff? Fill plug on the side and drain plug underneath?
And how about the transmission? Do you have to drop the whole pan (and does that completely drain it) or do you have to suck it out? What does that entail - just a new gasket?
Do you fill it back up through the dipstick hole?

Most transfer cases do have a drain and a fill plug, and would be done the same way as the axles. For the transmission, you have to drop the pan (use a big drain pan because it can be messy). I take the pan bolts off starting at one end. I will leave one or two bolts at the other end tight untill I have the drain pan set up under the end I started removing bolts from. I then hold the pan with one hand and take the last few bolts out slowely, allowing the pan to drop on the other end allowing the fluid to spill into the drain pan. Once you get the pan off you will want to clean out the pan really good and remove the old gasket. Most gasket kits include a filter and gasket, so you would want to replace the filter at that time. You then simply reinstall the pan with a new gasket. You fill the transmission back up through the dip stick pipe. Most transmissions take 4-5 quarts for a pan drain and fill, although the transmission holds about 11-12 quarts including the converter. I'd start with putting back in 4 quarts and starting the engine, letting it warm up and check the fluid level untill you reach the full mark on the stick.

I have the same rig as you an 03 granite 4x4. The transfer case as i remember is easy but a littl bit of a pain. Drain plug is in the front fill is in the rear up on top. A fluid pump would have made life easy but not nesc.

Tansmission: Theres a drain plug on the bottom. I did a drain and fill at about 50k and the fluid was still bright red. Now i do a drain and fill about every 4 oil changes. Figure any added protection i can give the tranny is good. Fill through the dip hole.

How neccessary is it to use the nissan brand transmission oil?I have been doing drain and fills like every 35K just did my second one and now trani is slipping from idle to first immediatly after change.

It doesn't have to be Nisan branded fluid. Just follow the recommended equivalent listed in the OM. I inquired at the dealer about the difference once and the guy behind the parts counter told me that they were the same. He said they did stock the Nissan branded fluid but it was the same stuff only more expensive. since they never sold much he didn't know how old his stock was and recommended that I just pick up a quality name brand fluid from a parts store.

-Saturday