The spin on transmission filter is extremely easy to change and only about $10, I do mine every other oil change.
The differentials are pretty dang easy to drain and refill as well. They both have drain and fill plugs, so you don't have to pull the cover. For the front one it is easier to fill if you have hand pump with a small hose you can screw onto the gear oil bottle (you can buy these for cheap from many different places), at stock height it's a bit difficult to get a quart bottle up there without it. For the classic trucks you only need 7 quarts to do both differentials, I believe the new trucks are the same.
06 LBZ CCSB
With some stuff.