The following describe the steps to take to setup your existing domain to point to your new website. If you do not already have a domain name, you can register one at GoDaddy or NameCheap.
Step 1: Update Your DNS Record
Login to your domain registrar and update the "A" record for your domain name to point to the IP address of your new website
Step 2: Update Your WordPress Settings
Go to Plugins > Installed Plugins. Make sure the "Site Address Migrator" plugin is Activated. If not, click the Activate link.
Next go to Settings > General and update the WordPress Address (URL) and Site Address (URL) to your domain name.
NOTE: Once you update these settings, you will not be able to access your website until all the DNS changes have propagated through the internet. You can use the following website to check the status of the DNS propagation (the A record should show the IP address of your server):
If the DNS propagation appears successful but you are still unable to access your website (or if it still showing the old website), first try shutting down and restarting your browser. If that still does not work, you will need to clear you computer's DNS cache - for Windows, open Command and type in "ipconfig /flushdns". For OSX, open Terminal and enter "dscacheutil -flushcache". Then shut down and restart the browser.
Step 3: Enable SSL For Membership & Event Pages
See our help page on "Setting up SSL for Your Website".
Step 4: Update Your Organization Settings
Go to Membership Works > Organization Settings > Integration. Update the URLs under the Website Integration section to reflect the new domain name (don't forget the "https:").