On the Manage Site page, click the arrow next to your site name on the top left.
In the Websites area of the Select a service window, locate the site you wish to delete the click the Dashboard button.
On the Manage Site page, click the Delete site icon under Site Actions.
In the Delete Site dialog, confirm that you wish to delete the site by clicking the Delete button. Note: You can't delete a published site.
Please note: You will not be able to give a new site a site name which was previously used on a deleted site. A new site will require a brand new site name.