How can I change my domain name on my online store?

[Hyoro14]

I bought a domain from shopify upon opening my own shop, but now due to rebrand project in the same onlineshop account, I'd like to change the domain name. Are there any functions to change the name. Or, do I need to remove the domain first of all, and to buy a new domain from  Shopify? If I remove the domain, the current domain will be canceled automatically and I don't need to pay for the renewal fee? 

Kindly advise me.