I am sure some have already figured this out, but I thought I would share in hopes of helping someone. As I get older my hands hurt more and more and handling the tiny rivets for the skins is hard. What I found is that if I ‘sprinkle’ a line of rivets over the holes, I can just use my finger tip to slide the rivet into place. The countersink helps the rivet just sort of tip into the hole. This doesn’t seem to work very well on vertical surfaces for some reason Just sharing in hopes of easing someone else’s pain a bit too. - Jason Kreidler