Remove right backrest side section

NOTE: Description is for left component only. Procedure on the right side is identical.

Remove armrest side section

Grip behind backrest side section (1) from above and unclip backrest side section (1) to the front from detent (2).
Guide out the backrest side section (1) from the rear seat in arrow direction and remove.

Courtesy of BMW OF NORTH AMERICA, INC.