The bottom edge is held onto the metal door with 3 or four snap in clips or screws, I don't recall which on your S13, but I think it was screws on mine. If it's screws, you'll see them and unscrew them, if it's clips, you'll just start pulling the door panel up as they pop free. Try pulling from the lower front corner first since it's easier to grab the door panel from there. You remove the screws and handles as shown in the video, unsnap/ pop off all the clips by pulling the lower edge away from the door, working your way up the front and rear edges. The top edge is the last edge to remove, it overlaps the top of the door along the window. Once the panel is free and kind of pivoting on the upper edge, you lift the entire panel upwards and off the lip of the door. Installation is reverse. You can do it. While you're in there, you'll have access to your speakers if you wanted to replace or remove those.