WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
Open pliers (1).
Place optical fibre (2) in cutting device (3).
Close pliers (1) and remove optical fibre (2).
Fig 1: Identifying Cutting Device And Optical Fibre