Started the lens by finding the centre of the two piece lens. Used the metal snips to cut the plastic and then I taped it to the wing tip and roughly drew the outline of the recessed area.
I then took the plastic to the belt sander and removed it to the line and then replaced back on the tip.
After about 4 adjustments, the lens fit pretty good. I then used 200grit paper smooth the edges of the plastic.
I'll finish off by adding the two nutplates to the wing tip.