51 21 370 Removing and installing/replacing cover at bottom left or right on front door

Detach cover (1) in direction of arrow from front door (2).

Fig 1: Detaching Cover From Front Door

Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Catches (1) of cover (2) must not be damaged.

Cover (2) has an aluminum insert (3).

Only press on catches (1) when installing otherwise cover (2) will become uneven.

Fig 2: Identifying Cover, Catches And Aluminum Insert

Courtesy of BMW OF NORTH AMERICA, INC.