found this in some site. don't know if it'll help.
"The clip is in a "C" shape, with the opening pointing toward the knob. The
clip is behind the washer on the window crank.
Roll the window about halfway down with the knob of the crank pointing
up. Get a flat blade screwdriver and insert between the crank and plastic
washer and twist the screwdriver while turning the crank. This will
probably push into the opening of the clip and not allow it to turn, and
should push it off the crank handle, allowing you to slide the crank off"