51 21... Removing and installing left or right lock barrel of front door

WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.

Necessary preliminary tasks:

Remove CARRIER FOR OUTER DOOR HANDLE

Release screws (1).

Remove gearing cover (2).

Fig 1: Identifying Gearing Cover With Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Press down latch mechanism (1) slightly.

Turn lock cylinder (2) in direction of latch mechanism (1) and remove.

Fig 2: Turning Lock Cylinder

Courtesy of BMW OF NORTH AMERICA, INC.