You can Private Message me or Don (or any Moderator) w your new username choice, and possibly a 2nd choice, in case the 1st is already in use, if you dont want to post them in the open forum.
Admin can/will change it for you. Might take a day or so, once they get the new choice.
Continue using your current name and password until it no longer works. Once it quits working, log in w the new user name using your CURRENT password (it wont change).