How to Hide CarDealerPress Admin Menus

function plt_hide_cardealerpress_menus() {
	//Hide the "CarDealerPress" menu.
	remove_menu_page('cardealerpress_admin');
	//Hide the "CarDealerPress → Admin Settings" menu.
	remove_submenu_page('cardealerpress_admin', 'cardealerpress_admin');
	//Hide the "CarDealerPress → Help" menu.
	remove_submenu_page('cardealerpress_admin', 'cardealerpress_help');
}

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

Where do I put this code?