Step 5: Drills the power rails plates
Simply drill out holes in the plates. The holes size depends of the screw you will use.
I use #6 wooden screws.
I use a metal punch to mark where I wanted the holes. This will help you center the drill bit when drilling.
You could use a sharp nail and a hammer to mark the metal instead of using a metal punch.
After drilling I use a big drill bit to scuff the metals bits. ( By hand )