WARNING: This page is about a different car, the 2008 BMW 760Li, 2007 BMW 760Li, 2006 BMW 760i, and 2006 BMW 760Li. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Circlip Pliers
Courtesy of BMW OF NORTH AMERICA, INC.
Note: External circlip - With long legs, 90° angle