51 21 003 Replacing door detent (lock striker), front left or right
WARNING: This page is about a different car, the 2008 BMW 535xi. However, it is still accessible from the selected car via links, so may be relevant.
Release screws (1) and remove door detent (3).
Installation:
Basic adjustment via crosswire on B-pillar (4) and notches (2) on door detent (3).
Tightening torque 51 21 3AZ .