How to change the username & password of cpanel phpmyadmin

Log into your cPanel
Under the Databases heading, click the MySQL Databases link
A database does not have a password to reset, but instead we are needing to reset the password for the user assigned to the database.

At the bottom of the page, under the Current Users, look for the user of the database then click on the Set Password icon in the Actions column. Remember that the database user you are modifying should be the assigned user for the database that requires the password change.

On the MySQL Account Maintenance page, enter the old password for the user and then enter the new password you would like. When finished, click the Change Password button.