I wish I took more pictures, sorry I didn’t. I cut a flange a little larger than the hole, same size as the diameter of the mounting flange on the fuel pump. Drilled holes (3) in the flange, and the tank, pushed the studs up through the flange and the tank and welded them in place. The tabs on the top are held in place with nuts and sandwich the tank between the flange and the pump. The gasket I cut from thin rubber gasket material I got from McMaster Carr. Can’t remember the thickness I used. Zero problems with leaks ever. Hope that helps.