I just got an HD Tivo. It is going in a place where an existing DirecTiVo currently is (meaning there are two lines running from the 3LNB dish to that spot). If I transfer those two lines from my existing TiVo to my new HDTiVo, will the HDTiVo work? Or does something else need to be changed out? I'm just wondering if I need an installer to come out or not. I live in LA and don't plan on mounting an antenna.