I couldn't figure out why I could not get my 3/16" temporary hinge pin (center picture below) to go through. Well, the plans didn't mention you need to up-drill the hinge bracket holes to 3/16"! Once I did that, I could get everything to pass through.
I used a much thinner, stiff wire (bent) as the initial temporary hinge pin, so I could get an initial measurement for cutting the skin. Until you cut the skin, it's tough to get the 3/16" temporary pin, or a 3/16" bolt in place.
