52 13 050 Replacing left or right lumbar cushion on front seat (normal/semi-electric)
WARNING: This page is about a different car, the 2010 BMW 535xi, 2009 BMW 535xi, and 2008 BMW 535xi. However, it is still accessible from the selected car via links, so may be relevant.
Operation is identical to:
Replacing LUMBAR CUSHION ON FRONT LEFT OR RIGHT SEAT (normal/electric)