Help needed removing seatback

Hey, I'm trying to remove a seatback for the driver's seat on a 2003 silverado lt. I had some broken motors and am switching the guts, but I cannot for the life of me get the side closest to the door to come loose from the main seat frame. There is one bolt that I can find about an inch above the upholstery and removing this didn't loosen it up at all! The other side came free and clear with one bolt. Any help would be greatly appreciated!