61 13 ... In-Line Plugs, 15-Pin, System D2.5
WARNING: This page is about a different car, the 2007 BMW 550i and 2006 BMW 550i. However, it is still accessible from the selected car via links, so may be relevant.
Carefully pull external connector (1) in area of retaining lugs (2) slightly out.
Pull internal connector (3) as far as it will go in direction of arrow.
With special tool 61 1 132 (ejector), press back arrester hook (4) of appropriate contact and pull out cable.