Changing your own username is not currently an option on Phantasy Tour. However, this option is being contemplated for a future release (visit the Feedback forum for current information on planned features). In the meantime, username change requests are accepted through the Supprt Desk and are considered on a case-by-case basis. There is no guarantee your requested username will be granted. You can reach the Support Desk by clicking the "Support" link at the bottom of any PT page.