BMW Z4 (E85) cylinders must be removed from the top frame as a complete unit. Do not at any time remove the rotating arms from the cylinder as this can damage the pinion gear. After removing the cylinder assembly from the top frame, remove all hardware and sensors except for the rotating arms.
Photos 1 and 2 show the two sides of the cylinder with the attached arms and all other hardware removed.
Please send us only the parts in the photos: