You can easily update your account details by visiting the SETTINGS / PROFILE page here:

You can update your NAME and LAST NAME if you made a spelling error when signing up.

Please note you CAN NOT update your email, once you register that email is permenat and can NOT be changed.

You can also update all of your account settings from this page like your USERNAMES for each level you are a member of.

You will only be able to update usernames for levels you are member, if you are not a member of a specific level, you wont be able to see or update the username for that level.