Erase Xbox 360 Hard drive?!

Hey i was wondering how you would erase your xbox harddrive?

ive got so many accounts on their and live accounts becouse of friends that stay over and want a account all to them selves.

and it looks messy. so id lyk to start it all over.

i want to do this without going to a shop and paying £60 for a new harddrive becouse of friends...

if you have any advice please tell me.

:)

cheers man!

helped me alot.

hey i just bought a xbox 360 pro 60 gb console and wen i was creating a profile i went in to settings and changed one of the tv settings from 480p to 1080p then the tv screen went black and i cant get no picture now and i also have a 1080p plasma HD tv so do i need a HDMI cable to play 1080p and what i was wondering is how do you delete or reset your memory/hard drive with out have a picture? send me back an answer please i really need the help

hey just switch it back to regular tv not hd on the back of the xbox it should be located on the wire that connects to the tv and make sure u put the red white and YELLOW cable back in.. go change ur setting to what u want again and switch everything back again to hd