They are held in an encrypted form in the mysql tables, I do not think you can (easily) unencrypt the password from the mysql data.
In settings.php you should be able to enable the “reset password” feature (off by default) which will allow you to reset your password via a link that then becomes visible at the log in screen. However this requires the email settings to also be configured correctly in settings.php and swift mail to be installed and working.
What will be easier is to enable the “multi-user” feature in settings.php and create a second user (new account) and then use phpmyadmin to copy the newly created encrypted password entry in the mysql tables from the new 2nd user to the original user, so the original account can then be accessed using the same password as the new user. You can then delete the 2nd user or just leave it dormant.