The user name of your Facebook profile can be changed in a few simple steps." https://worldzo.net/this-page-is-not-eligible-to-have-a-username/
Follow these procedures to change your Facebook name:
1. Look over our naming conventions.
2. Click in the upper right corner of Facebook.
3. Select Settings from the drop-down menu under Settings & Privacy.
4. Pick a name for your character.
5. After you've entered your name, click Review Change.
6. After entering your password, click Save Changes.