The front sill in question is held on by 7-8 1/4" bolts if you remove them you might be able to do it. Mine just snapped off when I wrenched on them. One idea for you, I took and upgraded the long bolt through the center to 3/8" all thread and used a washer/nut on both ends of the bed panel to hold the thread length sticking out to the proper dimension. It is recessed on the end where the bed side attaches so the nut/washer are not visible once it is assembled. Makes it really easy to get on and off as you work on the sides.