Remove output of WordPress head

functions.php

<?php // This File will be read by the wordpress engine, handle with care

// =============== Remove some output of the wp_head() function ===============

remove_action( 'wp_head', 'wp_generator' ); 		   // Remove the WP version in the generator tag
remove_action( 'wp_head', 'feed_links', 2 ); 		   // Remove the links to the general feeds: Post, Comment and Alternate feed
remove_action( 'wp_head', 'feed_links_extra', 3 ); 	   // Remove the links to the extra feeds such as category feeds

//remove_action( 'wp_head', 'rsd_link' ); 		    // Remove the link to the Really Simple Discovery service endpoint, EditURI link
//remove_action( 'wp_head', 'wlwmanifest_link' ); 	    // Remove the link to the Windows Live Writer manifest file

remove_action('wp_head', 'rel_canonical');		    // Remove canonical link
add_filter('previous_post_rel_link', 'ac_remove_helper' );  // Remove previous link
add_filter('next_post_rel_link', 'ac_remove_helper' );	    // Remove next link

// Helper function for remove actions
function ac_remove_helper($data) {
	return false;
}

// Untestet stuff
//remove_action( 'wp_head', 'index_rel_link'); 			// Remove index link
//remove_action( 'wp_head', 'adjacent_posts_rel_link', 10, 0 ); // Remove relational links for the posts adjacent to the current post.

?>

I have no idea, why the following implementation is not working (at least not for me):

remove_action('wp_head', 'previous_post_rel_link', 10, 0 );
remove_action('wp_head', 'next_post_rel_link', 10, 0 );

But I found the helper method solution, which works fine :)