Run Registry Setup
Run the Registry configuration script. Be sure to enter the username that will be returned by your web server's authentication engine. For example, under Apache this corresponds to $REMOTE_USER.
$ cd app $ ./Console/cake setup Enter administrator's given name > Pat Enter administrator's family name > Lee Enter administrator's login username > plee@university.edu
Be careful with file ownerships here. You may need to run this command as the web server user or as root. Make sure the cache directory (wherever app/tmp points to) and all of its subdirectories and files are writeable by the web server. chown -R and chgrp -R may be in order.
setup is intended to be run once. After you run it, you should be able to login via the web interface and make whatever changes you need that way. If you need to run it again, the easiest approach is to drop the database and start over.