Do you mean in a DirectAdmin hosting account? If so you should be able to add one then delete the old one, in Domain Management but only if your hosting provider allows you more than one domain because you can't delete a domain if there's only one. You should, though, be able to rename a domain in your account.
For help you'll need to ask your hosting provider because we have no access to your account or the server on which it runs.
If you mean at your registrar, then ask them, though likely not.
Jeff