61 13... Inline connectors, 6-, 8-pin, System MQS
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2015 BMW Alpina B7L, 2015 BMW Alpina B7, 2015 BMW 750i, 2015 BMW 750Li, and 2015 BMW 740i. However, it is still accessible from the selected car via links, so may be relevant.
Press lock (1) in direction of arrow and slide connector forward.
Press locking hook (2) downward and slide lock (1) out.
Press down retaining hook (1) with screwdriver and pull out cable with contact towards rear.