Have an administration port that you run things on as well. Just create  a second virtual server in IIS and extend your sharepoint  instance to that port as well and make sure anonymous  access is turned off. Sure, you're using something that's off port, but it allows you to do things behind the scenes.

Since you turned on anon access, you're logging into the Sharepoint site  as
the IUSR, not an account that has admin  rights. There's a link here talking
about different anonymous  architectures.

If you try to do administrative tasks, you should get prompted for
credentials. So, try entering the URL:
http://[portal]/_layouts/1033/User.aspx

Where [portal] is the domain name for your portal. Enter your
administrative credentials and you should be in. If this doesn't work,
verify that Integrated Authentication or Basic Authentication are turned
on for the IIS Web Site.