Getting out a hard drive...

[riksowden]

I've found someone who wants a computer tower (which I have one of, currently serving as a bedside table, because I've totally failed to get rid of it) but there is still some data on the hard drive. I don't have a graphics card in there to be able to hook it up and so delete things from their/reformat it.

Can anyone suggest a good way to remove the data from the hard-drive (or how to remove the hard drive itself - I wouldn't know what one looked like if it came over and bit me!)?