How can I clear the contacts list form a razr cell phone?

I need to erase the contacts list on a Razr cell phone. Is there a way to clear them all at once or do I have to go one by one?How can I clear the contacts list form a razr cell phone?
I think you need to do it on by one. I was thinking you were on AT%26amp;T, because on AT%26amp;T phones there is an option to erase all