This WOULD have been a normal job except I was like....those drain plugs are allen and they are huge. I don't have anything that big. Apparently it's a 14mm allen driver. I ALMOST jury rigged it with a 14mm head grade 8 bolt and some jamb nuts but decided I had to go to O'Reilly's in Warwick to get a set. I got a 12, 14 and 17mm. "They" say that I will end up with some new tools with this car. They were right. All sizes of E sockets on this thing, for example. I will need a bigger set eventually but not today. The rear calipers are held on by E18 and apparently they are SUPER tight. But I digress.
Back home the fill plug loosened pretty easily with just a 1/2" ratchet. Then the drain plug came out fine and I drained it.
To fill I screwed around with different options and ended up using my old (but unused until recently because I forgot I had it) large fluid syringe. Looks closest to this:
https://www.amazon.com/Lumax-LX-1185-Bl ... ve&sr=1-24
Anyway it worked reasonably well though the diff fluid is quite thick. Of course it's a Mercedes so it has to be different. It takes 85W-90. That's right. Not 75W-90. Not 80W-90. 85W-90. Which I've never heard of before.
Anyway, filled it up until it spilled, put fill plug back, done. Pretty easy. Nice, meaty cast iron diff, too.