Take off the screws holding the hard drive firm with a screwdriver. Pull out the top plate; you can also use a screwdriver to do that. Once you've succeeded in taking out the plate, you will see your drive platters, disassemble the platters, and other internal components.  About three screws are keeping the platters firm, so the right screwdrivers to take them off. Exposing your platters to air and holding them with bare hands has an extent of damage to the drive. To ensure your hard drive is destroyed, you still have to scratch the platter's surface with any sharp object.