You can delete cookies already on your computer depending on which web browser you use.
- Internet Explorer: http://support.microsoft.com/kb/278835
- Firefox: http://support.mozilla.com/en-US/kb/Deleting%20cookies
- Chrome; http://support.google.com/chrome/bin/answer.py?hl=en-GB&answer=95647
- Opera: http://www.opera.com/browser/tutorials/security/privacy/
- Safari (v3): http://docs.info.apple.com/article.html?path=Safari/3.0/en/11471.html