Questions about removing seats and center console

I'm having trouble removing my seats out of my 01 GMC Sierra.I want to remove my center console and sell it on ebay. I can't figure out what size of socket that fits the damn front 2 bolts located in the front of the seat rail. The back 2 i got loose and i used a 7/16 socket and it worked great but it's the front bolts i cant seem to find the right size. Does anyone know or have any advise? Sorry im a Newbie.