I am trying to get a used electrical driver's side back door

Okay, go to http://www.car-part.com/ Enter in the information about the vehicle (the VIN search works real good if you are unsure of the exact information).
Select by distance or whichever you wish. It will show you salvage yards around you that might have the door you are looking for. It does not list all yards though, just member yards who use Hollander and most U-Pull-It type yards are not listed because the inventory changes so fast. So look in the local area as well for those yards.

You want a door rear (side of vehicle) and electric windows LH.

The damage code and part grade as well as the description can be helpful and the pictures can really help.

The picture I added shows a damage Code 000 and part grade A 0 door.

While most of these places offer shipping, I would go in person, that way you can look at the part before you pay money.

Now as for replacement, They are bolt on hinges. Remove them from the door not the pillar. It makes lining up the replacement much easier. Depending on the yard they may just cut the wiring harness between the door and pillar or they may actually take it apart. That should not be an issue as long as you are is still okay.

Good luck and I hope you locate a nice clean door that matches in color and tint.
If you have more questions do not hesitate to ask.