Step 1: Acquire aluminum enclosure and a center punch

Step 2 put the template on the box

Step 3 punch some divots into the box

Step 4 Oh yeah tiny little marks

Step 5 Drill! Use a 1/8th inch bit. USE A DRILL PRESS THIS CANNOT BE DONE WITH A HANDHELD DRILL

Step 6 Measure the part

Step 7 Measure your step drill. Meh, a mil oversize is fine.

Step 8 Drill baby drill

Step 9 Woot.