functions.php

<?php

function change_post_label() {

    global $menu;
    global $submenu;
    $menu[5][0] = 'News';
    $submenu['edit.php'][5][0] = 'News';
    $submenu['edit.php'][10][0] = 'Add News';
    $submenu['edit.php'][16][0] = 'News Tags';
    echo '';

}

add_action( 'admin_menu', 'change_post_label' );

function change_post_object() {

    global $wp_post_types;
    $labels = &$wp_post_types['post']->labels;
    $labels->name = 'News';
    $labels->singular_name = 'News';
    $labels->add_new = 'Add News';
    $labels->add_new_item = 'Add News';
    $labels->edit_item = 'Edit News';
    $labels->new_item = 'News';
    $labels->view_item = 'View News';
    $labels->search_items = 'Search News';
    $labels->not_found = 'No News found';
    $labels->not_found_in_trash = 'No News found in Trash';
    $labels->all_items = 'All News';
    $labels->menu_name = 'News';
    $labels->name_admin_bar = 'News';

}
 
add_action( 'init', 'change_post_object' );

Does the line with echo ''; do anything?