2003 Server as Member Server

Hi everyone,
I want to do the following but am very very wary of doing it in a live environment.

I need to get a copy of our Active Directory from our Windows 2000 DC onto my Windows Server 2003 so that I can take the 2003 Server offline and redesign the AD Structure without making it a 2003 Domain.

What steps do I need to take to do this, as Technet doesn’t seem to offer an A to Z solution for this method.

Ta muchly.
The Young One