Tips for changing gearbox and transfer box oil needed

Yep.
Remembered that from last time and also ordered a 10mm key from Martin

rogerzilla wrote:

The no.1 tip is not to undo the drain plug before ensuring the filler plug can also be undone.
 

This is the best advice you will ever received, take it from somebody who had to help his friend take out a gearbox out because he drained it & the filler was so damaged it was only when on the bench with a chisel could we get it to move.

Picked the oils up this afternoon so planning on doing it Friday

Well
I finally got round to doing this job today, which turned out to be a bit more hassle than I remembered, from the last time I did it.
My last Jimny had a 3" lift as well as running 195/80 tyres, so on standard sized AT tyres and suspension, there simply wasn't enough working room under the vehicle (or I've grown, which is highly possible).
Ended up raising the rear on a set of ramps, then jacking to support the front on axle stands.

The oil that came out was rather less clear than the new stuff, but no metal deposits anywhere on the drain plug.

The filler plug on the gearbox was particularly tight, but gave with enough force.

The pump, certainly made getting the oil in easier, but is a very labour intensive job and got it done.
The 10mm key ordered from Martin, wouldn't fit either the fill or drain plugs on the boxes (neither was there enough access on the gearbox filler anyway, but the 3/8 end of a Teng ratchet fitted snugly enough, so used that.

A short run, sees the gearbox sounding quieter, which is nice, and it will get a longer run later to fully evaluate.

The 10mm key only fits a new clean plug.  I bought new plugs and put them back in with the key.  To prevent new plugs rusting, smear them with  high temperature waterproof grease like Ceratec.  Vaseline will melt and run off, because the diffs (ok, normally only the rear one) get quite hot.