Yes, install the phpMyAdmin package from www.ispconfig.org ( http://www.ispconfig.org/downloads/phpmyadmin-2.6.4-pl3.pkg ) using Management -> Update Manager -> Update.
Just download the phpmyadmin.pkg (you find the link under downloads on ispconfig.org) to your local machine. Login as admin in ISPConfig, go to Management -> Update Manager -> Update. Click the browse button and select the .pkg file you just downloaded and click install. Wait a minute while phpmyadmin is uploaded and installed. You will get a message when it is done. Now you should have a link to phpmyadmin in the Tools menu, next to the portscanner and whois. Follow the exact same procedure to install the webmail package. //Erk
Phpmyadmin itself does not have a password, the login credentials you are asked for are the username and password of your mysql database.