WARNING: You will work with a very powerful magnet. Be careful when you remove it from the hard drive, because you can bruise your fingers. And don't put the magnet near electronic devices, your wristwatch or your wallet, because you can damage your gadget or your credit cards. Don't tell I didn't tell you.
And you will need:
1 Dead Hard Drive (you will need only the magnet)
A metallic cabinet (or another big metallic surface where you can put your trench coat)