how do i remove the top plastic panel near the window sill and the door panel so i can replace it and the triangle piece on the window? what type screws do a 87 camaro have on the triangle piece

 

Take the arm rest assembly off, and the trim around the inside handle (if manual windows remove the window crank). Carefully, pull the fasteners that are attached to the panel out of the door, pull the bottom of the panel out (away from the door) slightly and slide the whole thing toward the back of the door (latch end) and lift up. That top plastic piece is attached to the panel, and clips over the top of the door, sliding it back releases the clips from the door. The triangle piece is held on by bolts, I think 10mm.