How to open underseat fuse box on 2003 Chevrolet Express 3500

Master lock switch on drivers door doesn't lock or unlock other doors anymore. Want to check fuses under drivers seat, but can't figure out how to open it. The seat is right over it, even slide back all the way. This is a Roadtrek camper van on a Chevy 3500 Express chasis.

Asked by for the 2003 Chevrolet Express 3500
March 28 2011 I have a 2011Roadtrek/Chevy 3500 Express with the same problem! can't access the under seat fuse box??? Anyone out there have a solution
there are clips on the right and left side that you need to pull awayfrom the fuse box then lift off the lid.