Migrate SBS 2003 to Server Enterprise 2003

I am stuck with a bad situation… I am working with a SBS 2003 Domain on a box that is falling apart…

The management bought Server 2k3 Enterprise on advice from a friend with no experience… And now wants me to move the domain to a regular domain…

So I am trying to figure out how to migrate a SBS 2003 Domain on an old box to a new Server Enterprise 2003 Box… But I do not want to use the Transition Pack…