Special tools required:

WARNING: This page is about a different car, the 2005 BMW 530i, 2005 BMW 525i, 2004 BMW 530i, and 2004 BMW 525i. However, it is still accessible from the selected car via links, so may be relevant.

00 9 317

Removing ski bag:

Fold back center armrest
Unlock handle strip towards top
Remove ski bag (1) towards front

Fig 1: Removing Ski Bag Towards Front

Courtesy of BMW OF NORTH AMERICA, INC.

Removing frame for ski bag:

Remove ski bag
Remove screw cover, release screws (1)
Tightening torque, see 52 26 6AZ in SEATS - TIGHTENING TORQUES - 525I & 530I (M54) .
Fold backrest forwards slightly
Feed in special tool 00 9 317 in area (2) between trim and frame and unclip frame towards rear
Remove frame towards rear bottom

Fig 2: Removing Frame Towards Rear Bottom

Courtesy of BMW OF NORTH AMERICA, INC.