To update your phone means you want to update the phones firmware. Is that what you mean? To do this go to Nokia site of your region and download Nokia Software Updater meant for N73. Before doing this you need to install the latest version of Nokia PC Suite (Ver 6.85.14.1) on your PC. Rest is all menu driven. Remember to take entire backup of the phone via PC Suite so that you don't loose your settings and phone-book.