Starting removal:

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Place windlass (1) on windscreen
Feed wire end into coil of windlass (1)
NOTE: Coil can only be turned in one direction.
Make sure the wire is always situated in the guide channel of the windlass (1)
Fit reversible ratchet (2) on coil and tension wire
Start by cutting lower adhesive bead
Grip second wire end in special tool 51 3 270

Fig 1: Placing Windlass On Windscreen
Courtesy of BMW OF NORTH AMERICA, INC.