Ok...my summary tips for folks installing their window regulators - my experience from a 1984 911 Carrera Coupe:
1. Follow Bob Tindel's advice - it's critical - use a cable tie as described if you don't want to remove the window channel or glass:
When the regulator is reassembled with the spring properly tensioned, it will be roughly L-shaped (impossible to put back inside the door without removing the window channel). Pull the spring-loaded arm down until it is aligned with the rest of the mechanism, and tie it in that position with a cable tie. Test fit the motor to ensure that it aligns with the mounting bolt holes and the regulator gear teeth.
The regulator can now be inserted into the door (without removing the window channel or glass).
Bolt the motor onto the regulator. After ensuring that the gears mesh, cut the cable tie.
Reinsert the rollers into the window track.
2. When putting in the regulator, tape the window about 3/4 closed - this will give you enough clearance to not damage the window.
3. After bolting on the motor, then lower the window down to near the bottom to easily insert the rollers into the tracks.
4. Push the window back up to almost closed to most easily put the 4 screws back in to hold the rectangular regulator body to the door.
5. Insert the two leads back on to the motor - there's no good way to visualize it while you do this ... so just do it blind by hand angling the leads slightly up and back to match the angle of the male terminals.
6. When testing the motor, remember that you have to install both window switches to complete the circuit. Hopefully you labelled the terminals of the wires with a silver sharpie 1 - 5 before you removed them .. if you didn't go right to this diagram
here.
7. The windows know when to stop at top and bottom. At the bottom you can replace the rubber where the regulator arms reach the bottom of the inner door using a
do it yourself gasket kit and cutting the pieces to shape - glueing them in with contact cement. See
here ... no need to order the rubber part. Don't glue the rubber over the drainage holes.
Regards and happy window regulator insertion!