How can I make an old hard drive unreadable?

Episode 1201 (40:08)

Gary from Pawtucket, RI

Gary has several old drives with data on it and wants to know the best way of destroying them so that they won't be able to be read. Leo says if he can read the drive, he can use Derek's Boot and Nuke (DBAN), which will write over the drive seven times to make it impossible to recover the data. His other choice is to take the drive apart and literally shatter the platters, if they're glass. Patrick Norton does this with a hammer. He could also drill holes into the metal platters as well.