Editors have permission to delete individual pages. Begin by navigating to the page you wish to delete, check it out and edit it.
In the Page tab in the ribbon, you'll see a button that says Delete Page. Once clicked, it'll ask you if you sure you want to delete it; click OK. The page will be removed from your Pages folder and the left navigation.
Note: If you need a subsite deleted and removed from navigation, you'll need to submit a TSC ticket. You can determine a subsite by the"default.aspx" in the URL. Keep in mind that if a subsite is deleted, all pages (as well as documents and images) that live within that subsite will be deleted too.