Help needed ntl boxes

hello all and can you go easy on me as I am a newbie.
Right I have ntl and as you will probably be aware the cards keep not working. What is the best and easiest way to be able to fix them myself instead of waiting 2 weeks for them to get re-programmed. I was told that a infinity usb pheonix programmer is the easiest method but I don't want to buy one if its not goiong to do the trick. Also what is required to do this task i.e software, leads.
Any help would be grateful.
Regards, Eazy