There are 2 screws at the upper corner under the roof rail weatherstrip, two at the lower corner at the jamb hidden under a flap of rubber that's part of the window seal, and one large one at the rear under the large trim that surrounds the window inside. Remove those and the window assembly just slips out.

I have details here. Select the #7 video clip "Weatherstrip Details"

http://70duster440.com/downloads.html