I want to put in a new 10' sub box under the rear seats. the fold out looks like its all part of the seat . a little help please thanks

 

I don't know how to remove the foldout but I'd be interested in buying it from you if you are going to get rid of it.

 

Remove the bolts that hold the seat down, the cargo tray sits under the mounts that seats are on. Once you remove the bolts the cargo tray comes right up. I removed mine in about 10 minutes. I also have the 10 inch sub box in my quad cab. 2 10 infinitys with a rockford amp, sounds great.