Nothing with curved parts is ever easy, and this was no exception. The goal is to form the Al rings and rivet them to the inside of the lens. It took a while to figure out which way the ring was supposed to bend, and then to attach, but I got there. Also, in the manual, it pretty clearly states that the plastic lens holes should be drilled oversize to make room for the countersink of the wing. I did that - on the second one I made. Then I had to de-rivet (i.e., drill out) the first one and do it all over again. When the lens is drilled oversize, you can no longer rely on using the 3/32 silver Clecos to line everything up, so the process was:

1) Bend the Al ring, then rebend it the right way, then put it in the lens and hold it tight with the 3/32 Clecos.
2) Drill holes for the 3.2mm countersunk rivets to hold the Al to the plastic lens. The manual suggests 6, but with the springyness and all the different "corners," I opted for about 10.
3) Countersink the 3.2mm rivet holes in the plastic.
4) Disassemble everything, deburr the Al, and drill the bigger holes in the plastic lens.
5) Peel the plastic from the lens away from where it will get stuck under the Al ring or under a rivet, re-assemble, using the new 3.2mm c'snk rivet holes to initially line things up, then the 3/32 Clecos through the lens and into the Al to hold things a little more firmly, especially when taking out the 3.2mm Clecos..
6) Take out one 3.2mm Cleco at a time and put in a 3.2mm countersunk rivet.
7) Repeat step 6 nine more times.
8) Redo the first one when realizing that the drilling of holes was forgotten in step 6.
9) Wonder how to hold the lenses when the time comes to screw them into the wing, then assume it will all be taken care of when the time comes.
10) Post pictures in the log and then move on.