How to update Domain Name on GoDaddy ?

Go to your GoDaddy product page.
Select Web Hosting, and next to the Windows Hosting account you want to use select Manage.
In the account Dashboard, in the Settings section, Account tab, next to the primary domain name select Change.
Select another domain from your account, or enter another domain name or subdomain.
Note: If you enter another domain name or a subdomain, you must update your DNS A record to the specified IP address.
Select Change domain.