The INSIDE hinge cover portion/area screw is tough to get at with the seats installed, but if you can get it out somehow, take the outside hinge cover screw out also, then take the two along the back near the bottom out, carefully flex the seat back cover slightly away from the seat frame hinge are and swing it rearwards an inch or two. Now lift the seat back straight up to slide the top holders, out of their brackets. Once you see the upper tangs clear the bracket that is screwed to the seatback at the top (that they slide into) it is off. Pictures might help but I do not have any handy right now.
Richard