This question is asked quite often so I thought I would write an easy tutorial to help you if you want to change the primary domain of your WordPress site, without doing an actual migrate.

It is best if you have WHM access for this. If you don’t you can ask your web host to do step 3 for you.  Ok here we go…

1. Backup everything. You can use a plugin or do it in your cPanel.
2. Ensure your new domain is registered and DNS is pointed to your webhost’s nameservers
3. Login to WHM  -> Account functions -> Modify an account.   Change the primary domain as required. Your site will be temporarily broken…. don’t worry we’re about to fix it…
4. Go to the WordPress Codex here, and follow the steps to update your Site URL. I find the functions.php option is easiest.  All updated? Ok now the site should be back online and WP admin should be working again… now it’s time to fix all the broken links and images…
5. Grab this simple search and replace script and follow the instructions to run it. You need to replace  all instances of yourolddomain.com with yournewdomain.com  and you can also take the opportunity to replace any other text that needs to be updated eg “Joe’s Old Business Name”  with  “Joe’s New Name”.
6. All done? Ok now check it. Check it really carefully. Happy? Delete the search and replace script.
7. You’ll probably want to park the old domain and make a redirect so that anyone visiting the old site will get redirected to your new domain. This is helpful for humans and ensures you don’t stuff up your Google ranks. You can do this via your cPanel.
8. Note that any email addresses associated with the account will change to use the new domain. If you prefer to keep the old ones then you’ll need to set them up afresh on the old (now parked) domain. Personally I’d suggest business email addresses should match the primary domain so I’d leave them as the new address, but recreate the old ones as an alias or auto-forwarder.

That’s it. Wow so simple. Should take about 15mins.