WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Crimping Tool (2327752)
Courtesy of BMW OF NORTH AMERICA, INC.
NOTE:
Basic pliers (e.g. in conjunction with die 54 0 230 for crimping the cables on the soft top in E93)