I have a client that has several 'regular' hosting accounts with us. He has decided to take advantage of using Cpanel's Add-On domains. Of course, since they are regular accounts, the domains are already in the DNS so CPanel will not allow to add that domain again. What is the best procedure to follow to avoid any downtime on the sites. I can have the client upload his files prior to making any changes, but was wondering if there was a way to establish the add-on domains without deleting his old accounts.