How do I change my main domain in my account?
To change the main domain in your account, first make sure that you are not currently using that domain as an "addon" or "parked" domain in your current cPanel account. Next, open a support ticket with the details of your new main domain. A support representative will be changing this for you as soon as possible.
If you want to use a domain you currently have as an add-on or parked domain, you first have to remove it from cPanel, and then ask for support to make this your main domain.
If you change your main domain, the content of the previous main domain will show up under the new domain. Your data will not be lost, it will simply be found under the new main domain you specify.