Reply to Modding vci-100: the cheap way

Alright so, i plan on doing my arcade mod on my vci-100, and i am such a cheap person, ( i bought my vci and audio 4 used) I am also going to buy the same arcade buttons ofr $1.50 each instead of off this site, -sorry djtt. Alright, so now i have a question. Clearly im not going to a machine shop so; what size holes do i need to cut into my vci-100, and what tool would i use? I own many off them, (like a soldering iron.)
Thanks, Glen