Removing domains
If you no longer want to associate a custom domain from a third-party provider with your Shopify store, then you can remove it from your Shopify admin, or transfer it to another Shopify store or domain provider. You can also remove subdomains.
Your myshopify.com
domain name can't be removed or transferred because you use your original myshopify.com
domain name to log in to your Shopify admin and identify your account when you contact Shopify Support.
You can choose a new myshopify.com
domain name one time. However, you still need to use your original myshopify.com
domain name to log in to your Shopify admin and to contact Shopify Support.
If you have a Shopify-managed domain, then learn more about transferring it to another Shopify store or other domain provider.