Learning from previous experience, I match drilled the rear spar doublers to the rear spar with the drill press. progress was a bit slow, but it was precise.
I then transferred the aileron holes to the doublers. As per the instructions I used a unibit to remove as much material as I could. I then tried to use files to finish the holes but progress was extremely slow and I had much material to still remove. I dug out the dremmel with a small sanding drum which worked excellent. At first it removes a lot of material, but as the drum wears down so does its ability to remove material allowing you to easily fine tune the cuts.
As soon as I was close enough, I cleco'd the doublers to the rear spars and very carefully used the dremmel to match finish the holes.
I drilled and de-burred the parts.
