rear quarter window access the assembly

How do I access the rear quarter window assembly on a 1996 Celica GT convertible. I'm not sure how to remove the interior panel. Two screws on panel under the bottom of the back seat. 1 screw at the top of the panel where the passenger door meets the body when closed. The window won't go up. gets stuck and pokes out the rubber trim. No problems with the window motor. Seems like the guide came apart from the roller. Not sure how to remove the rear interior panel. Do I need to remove the upper/upright, portion of the rear seats? where can I find a rear quarter window assembly diagram?