This is a quick hack/mod to a arcade button that allows illumination via a single LED.
arcade button (see http://www.sparkfun.com/products/9340)
and a super bright LED (see http://www.sparkfun.com/products/531)
Step 1: Remove the switch
1.) Gently pull the longest tab out of the switch
2.) the switch should now easily "flip up"
3.) you can remove it from the button