Hi, I have tried every technique I know to drill these little suckers out without damaging the dimpled skin. Some are ok but some enlarge the dimpled hole. I have been practicing on a bad skin and I can't get a whole row done without screwing up a couple. This problem is because the stiffners were a little long and wouldn't let the R-902 spar lineup correctly. I put a thin alum. piece under the stiffners and used a drimel tool to take the excess off, it left the stiffner end impossible to cleanup and I cut to much off 5 stiffners [3, 1/32 to short,2, 1/16 to short, min. edge distance] and want to replace the stiffners but can't drill em out good. these parts aren't expensive and put together fast but I'd rather just replace 5 stiffners if i can get them drilled out right. How the heck do you guys do this? Gene