RSS (RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a standardized, computer.

There are two ways.

1. Custom code in function.php

function ec_disable_rss() {
 wp_die( __( 'No feed available, please visit the homepage!' ) );

add_action('do_feed', 'ec_disable_rss', 1);
add_action('do_feed_rdf', 'ec_disable_rss', 1);
add_action('do_feed_rss', 'ec_disable_rss', 1);
add_action('do_feed_rss2', 'ec_disable_rss', 1);
add_action('do_feed_atom', 'ec_disable_rss', 1);
add_action('do_feed_rss2_comments', 'ec_disable_rss', 1);
add_action('do_feed_atom_comments', 'ec_disable_rss', 1);

remove_action('wp_head', 'wlwmanifest_link');

2. Using EC Addons