61 13... Inline plugs, 8-, 12-pin, System D2.5
WARNING: This page is about a different car, the 2013 BMW M3, 2012 BMW M3, and 2011 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
Move connector upper section (1) and the connector lower section (2) against each other in direction of arrow.
With special tool 61 1 132 (press-out tool) press back arrester hook (3) of appropriate contact and pull out cable with contact.