Light trimming of gear leg openinig to remove interference for level bottom edge. Pilot drill #40 on hinge halves. Mark 3/16" from firewall bottom edge. Removed bottom rivet from vertical stiffener to clear interference with hinge. Drilled (#40) and Cleco'd firewall side hinge. Updrilled (#30) and deburred hinge and interior firewall burrs. Rivet (CPP-42) hinge to firewall.