The bottom panels are retained by plastic lugs, but have at least one screw. start with the front panel, and try to slide it to the rear, this should allow the lugs to disengage. Be careful because it`s only cardboard. Once off you willl see a screw on the end of the rear panel over the arch.Unscrew this and again slide the panel to the rear.
Depending on your trim, you will need to unscrew all the window moldings on the top too.
Once off you can access the screws holding the middle panel with the speaker grill in it. This doesn`t detach from the panel at all.
The speakers are mounted on a metal panel attached to the van, and don`t attach to the plastic panel anywhere.
The pic below might help.
I`ll take some more when I get another cam, (I lost the last one)
http://s245.photobucket.com/albums/gg75/Mo...ale001Small.jpg