They are a *****, but with some determination it can be done. I bought a drill bit extension rod for a couple of bucks and used a metal hole saw to drill em out. They are at a hefty angle so it will be slipping around and not pretty, but who's gonna look in there anyway. By the way, they kick ass drilled out, some backfire pops on decelleration, but overall sounds great. Nice cruisin level and at idle they have a great throaty sound, not too loud if the cops are parked by you.