Having now gone through two final drives on one bike, I can't agree with
@TURBO200R4 more. It's very cheap insurance.
I just changed it on the 3R and forget exactly, but the torque setting on that drain bolt is very low, like 15 Nm. Get a torque wrench that goes that low (lower)- you'll need it for all kinds of things like fuel filter/pump tank gasket, etc.