The best way to connect your externally registered domain (General information on domains) with your ModelCentro site is by changing the name servers. You should be able to make these changes on your own or by contacting your registrar's customer support.
In case you haven't done it already, add a domain you already own to ModelCentro's domains section. (Connecting a domain I already own)
Change the name servers for your domain to the following:
If you cannot figure this out and you need to contact support at your registrar, here is a sample email you can send:
I would like to use my domain with a ModelCentro.com site. In order to do this, I need to point my domain’s name servers to the following:
I do not want to transfer my domain, but want to leave it registered with you.
Changing your domain's name servers will disable any email accounts you are using with your domain. Be sure to back up all email prior to making this change. If you prefer to keep those emails working, you might consider another type of domain set up CNAME. (Changing domain's CNAME record)
Once you’ve updated your name servers, it can take some time for the change to take full effect (up to 72 hours, but normally much less). ModelCentro will send you an e-mail notice once your domain is set up. If you notice that you still see your old page or an error message when you load your domain, don’t panic. Give it a few hours, and then try clearing your browser cache.