A forum user Franco B created a routing template for just this purpose:
http://forum.arcadecontrols.com/index.php?topic=103416.0However, to do it on the cheap if you don't have a router it's pretty easy following these steps: (This is how I do it anyway).
1) Grab a template here, print it out and tape it to the CP (Make sure it's printed in the correct size of course):
http://slagcoin.com/joystick/layout.html2) Drill a small pilot hole in each button hole on the template all the way through from front to back. Remove the template.
3) Get a 30mm Forstner bit (I usually order them on Amazon, they are hard to find at Home Depot). Put the center of the bit in the pilot hole you just made. Drill 1/4" deep. Do not go all the way through. Do this for all button holes.
4) Flip it over to the back. Get a 1-1/4" Forstner bit. Put the center of the bit in the pilot hole you just made. Drill 1/2" deep. Do not go all the way through. The holes on the back should overlap.
The end result should look something like this:

I've used this method on my 1/2" panel as well (I recommend 1/2" if you want to mount Sanwa sticks). You need to drill 1/4" on each side for that thickness.
Good Luck!
DeL