I have ruffus-designs.com domain, and hosting for it.
I would like to simply change the name to my new domain which is dxndesigns.ca, I want to keep all the hosting systems the same, but I want it to be dxndesigns.ca not ruffus-designs.com.
I think it's as simple as changing the dns it points to, but I am unsure.
If both domains are on Godaddy then just Login to your account > Web Hosting > Click on Manage ....
In the next screen you'll find all your hosting accounts. Choose the one you want to change and click on "Settings" option. A popup window will open showing your primary domain. Just change it and you're good to go.