First step was to cut out the AEX to the require dimensions in the plans and cut the 1 inch hole. I tried a 1 inch hole saw here and I did not have good luck, i don't know how I screwed it up, but I almost trashed one of the pieces. So I decided to run to harbor freight and buy a 1 inch step drill. This worked perfectly and quickly, I actually decided to cut the hole to 7/8 because I wanted a little more material and it's only lightening holes. Next I tapped the hole and trimmed the AEX. Drilled the reference hole to align the AEX.