Take the screws out that you can see. You don't need to take all of them out, but I can't remember which ones. Its not many anyways. Use a wide thin object and slide it under the enge of the plastic panel. Slide it along until you hit something near the edges of the plastic. They are little pry out clips, if youve taken plastic off something like this you'll know what I mean. Basically do this on the bottom and sides of the panel. Pry all of them loose and the panel is almost ready to come off. The top of the panel kinda hooks down into a groove near the window, it needs to be lifted up. You will only be able to pull the panel out a few inches, it is stopped by the linkages for the door locks and the wiring harness for accessories. Make sure you dont bend the linkages, I know from firsthand experience. They pop off at the panel, once those are off you can pull the wiring and take the panel out of your way. You can change speakers without undoing the linkages, but you have to be careful to not twist or let the panel hang. Bends are bad.
Ryan