61 13... Circular connector, 13-pin, system D2.5
WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2015 BMW Alpina B7L xDrive, 2015 BMW Alpina B7 xDrive, 2015 BMW 750i xDrive, 2015 BMW 750Li xDrive, and 2015 BMW 740Li xDrive. However, it is still accessible from the selected car via links, so may be relevant.
Special tools required:
Pull off rubber grommet (1).
Carefully pull out lock (2) in direction of arrow.
Move lower section of connector (3) in direction of arrow until retaining lugs (4) snap into release groove (5).
With special tool 61 0 303 , press down retaining lugs (6) of corresponding contact and pull out cable.