I am not sure about your model, but on my 83 300D, there are three bolts on the back side of the motor holding it to the regulator. They are in a triangular pattern and accessible with the door panel removed. You should use duct tape around the panel opening, to prevent the metal from slicing your arm as you work. After you have removed the motor, the window can be pushed up and held in place with either a wedge or a piece of pvc pipe, with a notch in the top, inserted through the panel opening. Using the pipe method you can reinstall the door panel until tou get your parts and the car will still look like it can be locked up.

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Dave
1983 300D Daily Driver