Move Featured Image Metabox

gistfile1.php

<?php 
function gmwm_move_featured_image() {

        remove_meta_box( 'postimagediv', 'metabox', 'side' );
        add_meta_box('featured_image', 'Add Featured Image', 'post_thumbnail_meta_box', 'metabox', 'normal', 'high');

}
add_action( 'do_meta_boxes', 'gmwm_move_featured_image' );