I started by checking the entire skin to make sure it was positioned 100% correctly, then I un-clecoed both sides and fwd edge until I could fire seal the center section fwd flange.

I then started riveting from the center outward and fwd, bucking through the avionics access holes and through the gap on each side where the sides were still loose. As I worked down both sides I continued to apply fire seal to the fwd flange. By using this process, I was able to get all of the lateral rivets down to about 5-6 of the longerons before it got tight enough that I couldn't get my hand in there any more.

I then finished fire sealing the firewall flange and clecoed all the remaining holes.