Switching the URL of my already live and hosted website

I am a newbie to dreamhost, and tried searching for this but could not find a clear and concise answer.

All of my domains are registered with GoDaddy. I have set up two of my domains to be hosted now with DreamHost. One, I set up first as a testdummy with a one-click install of Wordpress which was successfully set up. The second domain I just set up for hosting today and switched the Nameservers as specified in multiple threads and I also changed the DNS A Host in GoDaddy to match that of DreamHost.

Now, what I would like to do is change the URL of the website that is already set up with the first testdummy URL, to the new URL I just set up for hosting today. How can I do that? Is it possible, or do I need to redo the OneClickInstall and start from scratch all over again?

The easiest would be to create a Mirror of testdummy as your Main Site. Testdummy will still work, but you can change your WordPress settings so it thinks it’s your main site (it will automatically redirect to main site).

Did you do the Easy or Advanced One-Click? If it’s Advanced, there are some tricks you can try, but the right way to turn it into your main site will prevent the One-Click system from doing updates. Not that you need that since WordPress has a built-in updater that’s really good.