Not the demo, but the actual thing. I can't find it.

If you are trying to get to CPanel on your account, you just enter your address followed by /cpanel as in http://yourdomain.com/cpanel or http://111.111.111.111/cpanel. The alternative is http://yourdomain.com:2082 or http://111.111.111.111:2082

If you haven't been there, I strongly recommend also that you visit http://www.cpanel.net/docs/cp/

Finally CPanel has an up-to-date manual.