Cut the end rib on the fuel tank. Once again I don't have all the tools handy to do the job. Vans recomends using a fly cutter to cut the hole into the rib. Mine was out at the hangar and I wanted to do this NOW. I drilled a hole near the edge and used the nibbler to work around the hole. Took a little time but I think that the setup time of the flycutter would have been almost as long and I didn't run the risk of losing any body parts. I cut just undersize, mounted the stiffiner ring and scotchbrighted the inside away until it was a perfect match.
