How do I connect my Tivo Series 2 to comcast’s DCH70 cable box?

The coax from the wall goes to your cable box. Either coax or the a/v cables come out from the cable box and go into the Tivo. Another set of coax or a/v cables go from the Tivo to your TV. Your TV should stay on channel 3 or 4. You should have a serial cable from Tivo. Plug it in to the Tivo and the cable box. This allows you to change channels on your cable box. If you don’t have a serial cable, another option is some infra-red cables. Plug that into the Tivo and set it up so the cable box will be able to see the infra-red light signal from the Tivo in order to change channels.