wav3front go slowly.. but you will probably just need to edit the IP address of your "old" control server and change it to the new IP. Assuming your old server is already powered down.
Still, you should be able to work things out.. there are tips in this thread.. and Enhance support can always help you... so don't just follow my advice above unless you know the "old" server you are seeing in your control panel is actually the new one.
If your credentials don't work, I would be making sure you imported your database correctly.. the old credentials should work.
