the simple steps...
[0] you have already encrypted your data of course
[1] you run your secure erase util overwriting data at least 7 times.
[2] you remove the spindle-cover.
[3] you drill several holes of varying diameters through all the platters { avoid letting the drill slip and unnecessarily scratching the nickel plating }
[4] visit a local retailer and ask him to run the magnetic security-tag release wand over the platters for at least 90 seconds. { the her's often object }
you now have a pretty nice paperweight for your desk...right where you can keep your eye on it eh! remember to lock it in a drawer overnight though.