The back door panels are easy to remove;

Remove the upper trim panel by the window, by gently pulling until the clips pop.
Remove the small panel behind the handle to acess two screws, remove the two screws.
Remove the power window switch panel by gently pulling up until the clips pop and disconnect the plugs to the switches. There is a screw there to remove also.
Remove the two screws at the very bottom of the door panel.
Now pull the door panel upwards, disconnect the door cable by unclipping the plastic grommet and then remove the cable by turning it 90 degrees similar to on a bicycles brakes.

Hopefully this helps.

Edit - OK Im a dumba$$, the above is for supercrew not supercab, sorry.

 

At the top of the door latch on the supercab you will see an indention on the cover of the screws, just use a screwdriver to open it and then take out the screws. The access door is right in the middle of the latch.