Serious Trouble

I got a problem of installing WordPress on a subdomain before hosting the subdomain first. When I try to host my subdomain, it says WordPress was installed on it, but I cannot access the subdomain either.

Is there a way to remove the content in subdomain?
How do I go about fixing this?

The easiest way is to go to the panel for Manage Domains and click the Remove button in the Web Hosting column. If you installed WordPress with the Easy One-Click method, you’ll need to go to the One-Click section of the panel and use Manage Installed Applications to delete it.

That help a lot, thank you