Creating a hole for take out clip

I'm afraid we don't have a tool specifically to make those rectangular holes for take out clips. What I've done in the past when a take out clip was not present was to drill and install a temporary screw in the window track to act as a take out clip. After the balances and sash are reinstalled, I would simply remove the screw. 

If you want to go that route, I would use a screw similar to the 33-017. When you install it, leave some of the screw neck exposed so to catch and hold the balance in place. I would also recommend wearing safety glasses just to be safe.