61 13... Inline plugs, 3-, 6-pin, System Elo-Power 2.8
WARNING: This page is about a different car, the 2016 BMW Z4, 2015 BMW Z4, and 2014 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.
Press locking hook (1) in direction of arrow and disengage. Then unlock locking hook (2) and remove lock.
Press down retaining hook with screwdriver (1) and pull out cable with contact towards rear.