Its not a sealed box, just BMW reckon you don't need to change the oil ever, probably right technically, but it can't hurt though, and mine felt a lot smoother when changed for a top notch oil at 42k.
It still has a drain plug underneath and a filler/level plug on the side.
E90 330i 6MT gone. E91 335i 6MT gone. AMG E63 Estate gone. M6GC current...