I found the installation of the tanks to be quite complex mainly because it had to take place in my small garage with limited possibility to turn the construction around. The tanks have to be fitted in the correct position in relation to the cut-out holes for the tank lids of the upper skin, the tank feet, and the tank feet support on the lower part of the main wing spar. In order to do this there is a need to put the upper skin on with clecos and then drill holes on the lower side to fixate the tank feet with a couple of flush headed rivets. Well, I put some straps around the construction and lifted it up a meter to the ceiling and could do the necessary operations from below - with some effort.