52 26 ... Emergency actuator for rear seat backrest
WARNING: This page is about a different car, the 2005 BMW 545i and 2004 BMW 545i. However, it is still accessible from the selected car via links, so may be relevant.
Open luggage compartment.
Insert screwdriver for levering in snap-in hole of rear seat lock.
Press screwdriver to center of car and in so doing press supporting point (1) of Bowden cable outwards.
Courtesy of BMW OF NORTH AMERICA, INC.