51 21 140 Removing and installing/replacing complete lock barrel in left or right front door

Necessary preliminary tasks: 

• Remove CARRIER FOR OUTER DOOR HANDLE 

Release screws (1).

Remove gearing cover (2).

Fig 1: Identifying Screws And Gearing Cover

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.