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 the your BMW toolkit) in order to fit and remove it.
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Also referred to as oil filler cap.
These handlebar risers for your BMW R1250R let you sit up...
This cover for the axle pivot for all new R1250R bikes gives...
The joint is the mount / adapter for the footrest...