Just did this now, just under two hours.
Flange bolt was pretty tight, had a 18inch breaker bar on it with my foot with me holding onto the tree sliders and the truck in 1st gear low with difflock on (it was slipping with diff off :-. ) before it gave in.
I had not previously released the mud shield is supposed to be fitted to the flange and not seated within the transfer box casing. This made it simple a job of putting a couple of tweaks with center pop in the mudshield and tapping it gently back onto place until it was seated snug on the provided shoulder on the flange.
There was only a tiny amount of preceptable play in the output shaft so the bearing there is still good and the oil seal seems to be holding its own too so didn't need to disturb there.