Great! Yes, still reading. :)
Now, I have the USER_LOGINs that I want to delete. In order to do that, I need to change the element name from ADD_USER to DEL_USER. Ah, found
http://www.perlmonks.org/?node_id=838120. That pointed me in the right direction. I added:
$add_user->setNodeName( "DEL_USER" ); to the last line in my 'foreach my $add_user' loop. That did it! :)
Thanks again for the help!!