So had some spare time over weekend and changedd my mechanical flange around to fit it the right way round. In doing so i took some photos as well as some on a previous thread wanted to know the stages etc. So this might seem boring to most but odd ones might find useful.
So lower the back nut down on some string/wire or something of that nature. Stick your fingers through the new hole in your tank and pull it through.
On this picture ive put some plumbers bait to act as a seal before i fit the mechanical flange.