Optional: Click the Edit button for the database which needs its password reset.
MySQL set up page
Optional: On this next page, you will be prompted to enter a new password into two text boxes to verify spelling of the password. You may optionally create or change the database's description such as "joomla database" for your own reference. When you have completed filling out the necessary fields, click the Save button to update the changes.
Database Settings page
For additional information, you may want to reference: