I can't imagine that it would be too hard... The electrical part is pretty easy, a few wires between the doors for the switches and a power wire with a fuse.
I've never done it, so I can't say for sure...
Look for a parts truck to get the doors, motors, door panels, and switches.
Ford had a pretty good habit of making things easy on the assembly line, they most likely would have dimpled the places inside the door where you mount the motor assembly. I changed both motors out on my truck and even that required a little drilling.
If it's worth having, then it's worth doing.