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.
This cover for the axle pivot for all new R1200, K1200 and...
Feel safer parking your bike on dirt or asphalt with a side...
This cover for the open hole beyond the swingarm pivot is...