Here's how I did it on my 1988. I would assume that the window mechanism would probably be similar on yours.
Remove the door pannel and wire connections. Disconnect the power door lock mechanism. Disconnect the door opener mechanism from the inside of the door lever (small clip hold it on). For the manual door lock, free the lever from the "PIVOT POINT" near the rear of the door. Remove the large silver mounting plate. Once unbolted, it can be removed by tilting it out at the top.
With the window part way up you will be able to see (through two circular openings) and access the 2 nuts which hold the window to the rail mechanism. Mark where the window is before loosening. Set the window aside. You can do this without removing the window from the door, just set it out of the way inside the door.
Remove the 2 bolts in the top and 2 in the bottom of the door which connect to the window rail. Remove the rail, which has the motor on it. Replacement is the reverse procedure.