E30 Wiper motor

Hi,

I'm trying to remove the wiper motor to clean the grease off the
contacts as its growling and the arms are refusing to return to the
park position.

I'm attempting to get it out through the small vent hole on the
passenger side but at the moment I can't seem to disconnect the
electrical plug / connector. Whats the trick with this connector?
Please reply before I loose patience and cut the wires, thinking that
it might be OK to splice them back in later.

Thanks in advance,

Al.

Also if it turns out that I need a new/second hand wiper motor any
suggestions of where to get one appreciated!