Richard, I basically wrapped a piece of 180 grit from my roll (about six to eightinches longwill do)around the cardboard sleeve supplied with the kit. You will have to start it at an angle and just keep twisting until it makes it's way through the original hole. After that, test and sand until you get the fit you want. It only takes a couple of minutes per hole ( ten holes counting the fuselage) for about twenty to thirty minutes total. It's 8:00 pmright now and I already have the right wing prepped for sheeting and a wing tip. One suggestion that made it a lot easier for me was to tape both sides of the rib feet with a piece of 3/4" masking tape. Before I did that the feet kept breaking off when working the two 5/16"steel jig rods through the ribs. After taping the the feet to theribs not one broke off. With any luck,I'llget the left wing framed up tomorrow and both covered by Monday or Tuesday. Photos to follow.