Replacing current project

Good day. We have a current website and we want to replace it with a new one. I followed the steps in adding our domain but it is telling me that it is already added currently. Do i need to unpublished our current website?

Yes and you would need to remove the custom domain so It can be used on your new build. If you have prepaid for hosting you should reach out to support after migrating to credit the new site account.