Bluehost users can access cPanel to manage their websites. You can change a database user' password via a MySQL Databases tool in cPanel.
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How to change a database user's password in Bluehost
To change database user's password, please log into your Bluehost account first. Click the Advanced menu on the left and then click the MySQL Databases tool under DATABASES.
The MySQL Databases tool appears. You can create a new database and modify existing databases in this page. Also the list of current databases and the list of current users appear.
When you scroll down the page, you can see the current database users.
To change the password of a DB user, click "Change Password" next to the DB user whose password you want to change.
Then, the Set MySQL User Password page appears, where you can set the new password for the db user.
You can also change the DB user's password in other web hosting companies which offer cPanel for the management of the entire website.
Change the DB user password in the wp-config.php file
If you run a WordPress website and you changed the db user's password, you need to edit the wp-config.php file to reflect the change. If not, you will see an error message "Error establishing a database connection" when you visit your website.
To edit the wp-config.php file, you can access your web hosting server via FTP. You can also use the File Manager tool in Bluehost to edit it.