BAHAHAHA!!!
I'm thinking you open it up to see what it looks like, the throw it against a wall like you would a baby bird
There is no way to permanently erase a hard drive, you can format it by hooking it up to another computer. That will "erase" the drive, but data is still there that could be recovered by a professional.
But in short, the only way is to connect it to a computer.
With the right equipment, data off a HDD that's only been opened is quite piss-easy to recover. The only way to permanently to destroy all the data on HDDs is to smash the platters in to pieces and scatter the pieces around so that it's impossible to physically locate them.if you every open up a hard drive, it is screwed for ever!
Is there a way to erase a hard drive not connected to a computer, i.e. reset it?
Erasing a hard drive doesn't have to be destructive...
When you write zeros to a drive, it sets the value of the sectors to zero... Therefore, erasing all the data on the drive. End of story.
Data off a HDD completely written full of zero's even several times can be recovered with fairly high rates. Of course you need specialized equipment and techies doing that, but the point is, without blowing the HDD into pieces it's almost impossible to wipe everything off your HDD.