How to Hide myCred Admin Menus

function plt_hide_mycred_menus() {
	//Hide the "Dashboard → About myCRED" menu.
	remove_submenu_page('index.php', 'mycred-about');
	//Hide the "Plugins → myCred Setup" menu.
	remove_submenu_page('plugins.php', 'mycred-setup');
}

add_action('admin_menu', 'plt_hide_mycred_menus', 1000000000);

Where do I put this code?