Pilot drilled the HS-405 rib attatchment holes to #40 using demensions given in SEC D-D. Selected left side HS-702, HS-603PP, HS-706, HS-707 and HS-708 and cleco together. Drilled rib to sapr attatch holes to #30 (except HS-708 to HS-603PP). Un-cleco, deburr holes, cleaned out chips and re-cleco. Enlarged HS-708 to HS-603PP holes to #21. Cleco on the HS-801PP skin. Sliped the HS-404 and HS-405 ribs in place and marked aproximate hole location using skin as guide.