Window motor assembly picture?
Found a pic. Flat wound spring. Just have to figure out how to put it back on.
Regardless, you'll need to drill out the regulator. (You can only work with the spring with the regulator and motor off the car.) You put a bolt, washer, and nut through the holes in the regulator arm to keep it from chopping off body parts with the motor removed.
When it goes back on, you'll also need an industrial sized riveter and order the special steel mandrel, aluminum jacket rivets needed from GM. (Bolts or plain steel rivets will tear apart the door.)
Found a pic. Flat wound spring. Just have to figure out how to put it back on.



