Move WordPress site to root?

I have a client who is migrating a site to my hosting service. I use SiteGround hosting and it allows multiple sites on one cPanel account, but it is not WHM. The old website designer has abandoned the website and given her site files and the SQL database. I have come to find out that the site was built on a subdomain: demo.domainname.com The site is a Wordpress install. I uploaded the site files and created a new DB and imported the SQL database. I tried to go to the website (domain name not transferred yet) so I want to mydomain/domainname.com to see if the site would work. It"s not working and I guess it"s becasue the site was done on demo.domainname.com I went into the SQL Database to change the WordPress URL areas to domainname.com but that doesn"t work. How can I get this site to work on her top level domain at this point? Should I wait till the domain transfer is done and is pointed to my server to even sort this out? I was hoping to examine the site before the domain is done but I can't seem to. Live site URL: - Removed - Thanks in advance, Nat