First all the nutplates get riveted to the Z brackets, then all the brackets are bolted to the main spar (I had some difficulties due to some no so optimally placed nutplates).



Then the fuel tanks get clecoed to the spar and the alignment verified.



In the picture is the join between the right fuel tank and the leading edge. On this tank I have a small gap (less than 1/64 in) on the underside. The left tank fits perfectly on both sides.



Then all the drilling gets done, first drill the inboard Z bracket, then drill the junction plate between fuel tank and leading edge, then take the leading edge off, then drill the outboard Z bracket, then get the fuel tank skin off and drill the remaining Z brackets.
To finish the day I bolted the tie-down assembly to the main spar.