As stated above... 1/4 or any size drill bit and drill two holes thru
Fast and effective. I like it.
Once, years back, when I worked for a small software company, one of the QA folks showed up at my desk, hopping nervously from one foot to the other. Birdlike, she was. She up held a 4mm data tape and declaimed in a serious voice that it contained Highly Sensitive Customer Data and that it must be erased Immediately. I accepted the tape from her with both hands, like a
sararymon receiving a business card. I peered at it for a moment. And then I dropped it on the floor and jumped up and down on it, stomping it to bits. She backed away s-l-o-w-l-y, and never bothered me with trivial crap, ever again. Go figure.