Want to delete the customer portal users

Want to delete the customer portal users

Hi,

I want to delete few customer portal users, which I have added it for the testing purpose. I am only able to deactivate them but I am not able to delete them. Actually I want to add them as agents. As the e-mail id has been used while adding them in customer portal user, I am not able to delete them.

Please do the needful.

Thanks & Regards,
Kumaran Balasubramanian.