How to Hide mb.YTPlayer for background videos Admin Menus

function plt_hide_wpmbytplayer_menus() {
	//Hide the "mb.ideas" menu.
	remove_menu_page('mb-ideas-menu');
	//Hide the "mb.ideas → All plug-ins" menu.
	remove_submenu_page('mb-ideas-menu', 'mb-ideas-menu');
	//Hide the "mb.ideas → YTPlayer" menu.
	remove_submenu_page('mb-ideas-menu', 'wpmbytplayer/mbYTPlayer.php');
}

add_action('admin_menu', 'plt_hide_wpmbytplayer_menus', 11);

Where do I put this code?