Riveted VS skin to fwd spar assembly amd ribs. As this was the first riveting of skins for me, I went very slowly and practiced a good bit before getting started. I found some rivets to be tricky such as those closest to rib/spar intersections as well as both sides of the very fwd tip of the tip rib. I wound up drilling out 5 rivets and replacing. I've held off closing out the whole assembly as I wait for advice on replacing a marginal rivet, trying to weight the risks of leaving it in versus enlarding the hole.