Quick illustrated guide to a transfer box oil change

 

The drain plug
The level plug (note temp sensor to the right - do not touch that sensor!)
Another view of the level plug
The breather hose (used to fill with new oil)
A small improvised adaptor to fit the funnel to the breather hose
The funnel

The juice (600ml thereof)

Vaux part num 90443530

If it's impossible to find it, use a fully synthetic 75w90 like Mobilube1

(pics by TELVM, a ClubCalibra member from Spain)