2.15. Username Change
If you want to change your username, you can do this yourself by going to Manage Your Profile:
Remember, this is the name that will represent you throughout all Groundspeak websites.
Usernames must be between 2 and 20 characters.
If a username already exists and has ever been validated, or the username has been used in any way, then the username is not available.
Once you process your new username, your site statistics will remain the same. The geocaches and Trackables that you own will still belong to you under that new name, and all your found geocaches and Trackables will show as found by your new username. You do not need to transfer them. You may, however, want to update the "Geocache Placed By" field on all caches that you have created.