There is a drilling in the side of the plug in which you can put a size 3 Allen key or a Torx key T10 (usually found in your BMW toolkit) in order to fit and remove it.
See tools.
For spare parts see filler pipe (part number 7659578) and o-ring (part number 1340901).
Also referred to as oil filler cap.
Chrome cap II was created for covering the gear oil filler...
A cover made of aluminium with emblem. The mounting is...
Made of high-quality aluminium and fits all four valve twins...