unfortunalty you gotta pull the whole cover off to drain the oil, or just loosen all the bolts and give a good tap with a hammer to dislodge it from the gasket and just retighten when all the oil has drained out. then refill until oil starts coming out ofthe level hole and refit the rubber bung
Mate you dont even have to do that there is a DRAIN plug at the bottom just take that out let it drain out
Then replace the drain plug making shore that you got some sort of lock tight or some thing and make shore that its done up tight then theres a rubber plug at the top of the diff just pop it out and keep filling till it over flows and put the bung back in
P.S will help alot with a lowered car if you jack it up maybe because the panhard rod makes it abit annoying to fill also make shore you get the right gear oil for LSD or Single legger
It makes it much easier if unbolt the pan hard rod and get it out of the way too. I like using CRC red gasket because it's quick and easy. Apply it to the cover plate. Just circle all the bolt holes and then connect them. The only important thing is that there are no gaps. Put it on and do the bolts up finger tight and wait for it to dry (I think it says how long on the packet). Then tighten them up about another half turn (use your best judement) and add your oil.
just changed diff oil in my vr.
found easy way to do it was a short length of plastic pipe and fill a old washingup liquid bottle (or similar) connect pipe to bottle and gently squeeze.
worked well for me at least
you do have 2 loosen the bolts on the cover because the plug on the back is just under centre n there will still be oil in the diff. when u fill the diff up when the oil starts flowing out of the plug hole thats when its full.