WARNING: This page is about a different car, the 2002 GMC Safari and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Install the trim panel to the door.
Install the lace.
Fig 1: Removing & Installing Rear Door (E54) Trim Panel
Courtesy of GENERAL MOTORS CORP.
Fig 2: Removing & Installing Rear Door (E54) Trim Panel Lace