I recently did this repair on a Town Car. Once you get the door panel off you have to remove the rivets out to remove the motor. The instructions tell you to drill out the rivets. You can't do this because there is a pin in the center of the rivet head that keeps the drill bit from going into the hole in the center of the rivet. I used a die grinder with a cutoff wheel. Wow! That's the ticket.
You CAN knock out the center pin, then drill the rivet.................