1. Cut and drilled (4) F916C spacers. 2. Enlarged clearance holes on access and invboard seat ribs (4). 3. Cut out removeable section on two seat access ribs. 4. Drilled, dimpled, and rivited platenuts to (6) seat ribs. 5. Drilled F725B-L/R for future step installation 6. Clecoed all seat ribs to F704 aft center section.