How to Hide CMS Watchman Admin Menus

function plt_hide_cms_watchman_menus() {
	//Hide the "Watchman" menu.
	remove_menu_page('cms_watchman');
	//Hide the "Watchman → Dashboard" menu.
	remove_submenu_page('cms_watchman', 'cms_watchman');
	//Hide the "Watchman → Login" menu.
	remove_submenu_page('cms_watchman', 'cms_watchman_login');
}

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

Where do I put this code?