I just finished installing the lights into my tips today and have them fitted as best as possible until I have the wing covered. Josh is correct, go slow with the cuts you will find there is enough room for the lights but just enough. I took 1-inch wide blue painters tape and ran a line of tape as straight as I could as close to the edge of the fibergalss to get a completely straight line. I did this for both top and bottom. I then slipped the tip over the metal strips that are clecoed to the wing. You will need to work the wing tip back and forth, side to side as you get a nice fit. This takes time as does all parts of the build. It may seem confusing at first but as you go it will all come together.

I used a long block hand sander I made 4 foot long to work the edges down. As for final fitting, I will do that after the wing is covered. Once you pull the covering around the last rib this may or may not be an effect on the metal strips and that could slightly change the tip position.