I spoke to the dealer today about the process used by them, drain and fill via dipstick. The full empty and refill is done by disconnecting the pipe at the radiator and draining into a bucket while pouring in fresh at the dipstick - engine running.
Also - road only trucks change at 96000 Kms.(62000mls) approx
I am looking at changing the transfer case as I have done both diffs, Canada is Dexron 3 but how much and where are the drain plugs?