How do I solve this dilemma?

Hi,

Have a domain http://www.whalesafari.no that is linked to the following address where the site is located:

http://hvalsafari.eybjorn.com

Since the developer does not respond anymore, we have decided to move the site to a new web-host and use the URL http://www.whalesafari.no directly.

I have full admin rights to our site but no FTP access.

The question is, how to do move our site without having interrupts in the http://www.whalesafari.no URL? I was planning to move and redo the site on http://www.whalesafari.no before i removed the link to http://hvalsafari.eybjorn.com but the problem is then to access the admin-page on http://www.whalesafari.no… Any ideas????