After finally sourcing a 14mm Draper drain plug key socket bit I found the time to do the oil refresh.
The diff was very straight forward, I made sure that the fill plug came out first before draining and all went to plan. I thought the oil looked good as it poured out a kind of golden syrup colour. It wasn't until I opened the bottle of new oil that I realised that the new stuff is pretty much clear! So well worth doing.
Gearbox needed the cover removing and the fuel filter cover partially removing. The stuff that came out was thick black, so was well overdue and definitely explains the sloppy notchy gear change I had been experiencing.
I did have a bit of leakage from my pump, I went for one from Screwfix and I might have been a bit excited when pumping...causing the oil to pass the rubber bung part and leak out the wrong end!
All in a fairly straight forward job, gear change is much nicer now so worth doing!
Next job will be to remove the intercooler and give that a clean to see if I can free up some horses...