Trying to change primary website name

I am trying to change my primary website on Word Press to another name. I have registered the new domain name with Hostgator and have done the necessary change there. I want to also keep the old domain name directed to the website.

What do I need to do with Word Press to complete this task. When I now go on the new name, only one page shows up from which you cannot select to go to other pages.

http://www.vintagechinafinds.com New domain name