Disable RSS in WordPress
WordPress doesn’t come with the ability to turn off RSS. There are no really easy ways to completely switch off or remove your RSS feeds in WordPress for private or semi-private blogs. You could delete the php files themselves in wp-includes, but you’ll have to do this everytime you upgrade. Here is a better way to solve the problem:
Visit “Appearance” and “Editor” in your admin menu. Edit the “Theme Functions” file (functions.php). After the opening
remove_action('do_feed_rss2', 'do_feed_rss2', 10, 1);
remove_action('do_feed_rss', 'do_feed_rss', 10, 1);
remove_action('do_feed_rdf', 'do_feed_rdf', 10, 1);
remove_action('do_feed_atom', 'do_feed_atom', 10, 1);
If you change the theme you’re using, you will need to do the same for your new theme. You may also want to remove references to these now non-existent feeds in your themes header file.