The shelf should be flush with the bottom edges of the rails. The credenza bins include a file box for hanging file folders and a supply storage box. credenza. drill evenly spaced pilot holes for the bin bottom in the credenza sides and end. If proper file guide is not already in place, refer to paragraph for rivet, turn ends so that they are now parallel, and slip round hole over dowel-head rivet. Raise telescoping guard (8) so that bottom is halfway between frame and table.