How to Hide the "Combidesk - SnelStart" Admin Menu

function plt_hide_combidesk_snelstart_menus() {
	//Hide the "Combidesk - SnelStart" menu.
	remove_menu_page('combidesk-snelstart-settings');
}

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

Where do I put this code?