Remove Any Unnecessary Files of WordPress

How can we remove the /wp-includes/js/comment-reply.js?ver=20090102 script tag? 2 steps: first edit wp-includes/functions.php, add the follow code at the end of functions.php: function clean_header(){ wp_deregister_script( ‘comment-reply’ ); } second, edit wp-includes/default-filters.php, add the next line at proper place: add_action(‘init’,’clean_header’);