Note that the lock has been removed so the floor drops right in. There are short screws not see under the hinge that attach the forward edge of the box to the back of the battery box. Another screw goes in the side of the wall where the Propex outlet is and attaches to the side of the seat/battery box (not shown, would be in lower right hand corner of pic). This secures the box so there's no chance of movement when you step on it to get to the upper bunk.
