I'm on the fence on tackling the final drive oil. Most likely safer to remove the rear wheel so no oil gets on the disc. I don't have a breaker bar yet though.
I got none on the disc and a shot of brake cleaner would have removed it.
I was hesitating, expecting to wait until time for a new tire, but it was not difficult.
Entering through the disc slot (for check/fill plug) was a bit tight with an 8mm hex bit on 3/8" drive extension, but doable. Once broken loose, I used the hex bit, without the extension to finish removing the plug.
I checked the capacity of the Tupperware container before using it.
It fit on the inside of the wheel under the check/fill plug.
Only a couple drops came out when plug removed.
Had I the forethought to elevate the container, when moved under drain and when drain plug removed, there would have been less splash...but hopefully others will learn from my oversight. Also, should have moved wires and brake line behind tab, first. Brake cleaner cleaned up wires and brake line. A household degreaser (Dawn) removed splatter from tire sidewall.
Inserting tube into fill port was easy, but I made sure it was past the final step.
Home Depot has 3/8" OD, 1/4" ID clear vinyl tubing, 10 feet for $3.36, to flow from 1 quart bottle to final drive.
It fits on spout if spout is not cut too short and the other end fit into fill port well.
I did not change the o-rings, as they only were in service 1200 miles/5 weeks.