Deleting an account...but retaining the contact. How do I do this?

Deleting an account...but retaining the contact. How do I do this?

A former employee entered leads as "accounts," setting up dozens of accounts that we don't actually do business with. I want to retain the contacts in our database for emailing purposes and promotions - but the companies these contacts area ssociated with are not current accounts of ours.

Is it possible to delete accounts....but not delete contacts associated with the accounts that were created?

Sharon