Looks like you go to phpmyadmin.net and download phpMyAdmin 18.104.22.168. The newest version requires a higher version of php than is included in Elastix. Basically you extract it to /var/www/html. Fix the permissions to asterisk:asterisk . Go to http://yourservername/phpmyadmin--- and set it up. You can also use webmin to do mysql stuff and a lot more.
Read the documentation too I am sure they are better than my memory.
The thing I would wish is that once you have phpMyAdmin installed that there was a way to add it to the Elastix GUI (same thing for Webmin). Elastix needs a way to add user-installed programs to the "Extras" menu, or maybe a new tab called "Local Additions" or something. Basically it just needs to be a menu of shortcuts to other software you may have installed (phpMyAdmin and Webmin would be the big two that I could think of).