I had the plastic sliding piece break on the back door of my old SDL and had to take out the regulator. If you have the door skin off already, that is the hard part. There were just a few screws holding the regulator in place. The hard part is accessing it without ripping your arms to pieces.

The one clue I can offer is to follow the wiring. If I remember correctly there is an electrical junction near the top of the door. Open up the junction box and the wires will come out (with their connectors on). This allows you to remove the regulator completely.

I would recommend getting a block of wood to hold the window up and out of the way.
Again the usual tricks of replacement for any window regulator. It is a tight space and lots of sharp metal edges.

Good luck.