How do you connect a Tivo Series II to Directv HDDVR ?????

 I have  a Tivo series II receiver and  a directtv  hddvr  I keep reading that you can connect the Tivo to the DVR, It would be nice if the USB ports worked on the DVR but don't. How can I hook up my Tivo to Direct TV?

Tivo is model TCD24008A  and DVR is HR-23-700.