Well, it could very well be the motor. Taking the door panel off isn't bad. There are screws in the pull handle/armrest (you'll have to remove the plastic insert in the pull handle with a flathead.) Behind a tiny round hole in the handle lever area, and around the perimeter of the door panel itself. Once you pull that up and off, you'll see the clear plastic inner liner. With a exacto knife you can cut the black gooey rubber that holds the plastic to the door and remove the plastic liner (careful, you can reuse the liner by pressing the goo back together.
Once that's off you'll see the innards of the door itself. You can lock and unlock the door and see how the mechanism works. I'm not really sure how where the power motor for the door is, but while that's off it's a good time to inspect the motor and/or pull it out. It could be something as easy as a plug pulled loose. Who knows!
Good luck,
N.
