Host Gator should be the same as most shared hosting providers.
- Open cPanel and scroll down to Databases.
- Select “phpMyAdmin”.
- Document all your MySQL database names, server/port (probably localhost:3306)
- Return to cPanel and open “MySQL Databases”.
- Scroll down to “MySQL Users” and create a new user/password then add it to the Dolibarr database.
- Back in cPanel, File Manager and review your settings in /dolibarr/htdocs/conf/conf.php
If everything works now, remove the old username.