Load CSS in footer with wp coupons plugin

footer-enqueue.php

//dequeue our initial css file
function wpc_dequeue_css() {
	wp_deregister_style('wp-coupons-styles');
	wp_dequeue_style('wp-coupons-styles');
}
add_action('wp_enqueue_scripts', 'wpc_dequeue_css');

//print css file manually in footer
function wpc_footer_css() {
    echo "<link rel='stylesheet' id='wpc-styles' href='" . site_url('/wp-content/plugins/wp-coupons/css/style.css') . "' type='text/css' media='all' />";
}
add_action('wp_footer', 'wpc_footer_css');