If the door is the same as a Chevy, here is the trick. Remove the trim around the windows and take out the screws holding the vent window in place. Close the window, then, remove the hinge access plate at the bottom of the door. If you reach up through the hole under the hinge access plate, there is one bolt that holds the vertical channel in place. Its a tough reach but its there. A half inch socket with extension(s) will remove the bolt. Then lower the window and tilt the vent window assembly towards the latch side of the door and remove. It is sometimes helpful to take the door panel off and reach down through the opening in the door to get to the bottom of the vertical channel. However, there isn't anything you can reach that way that does much other than help you figure out what's going on in there.
