The Head End Unit is the user interface and display:
1. Drilled a 1/2" hole in my cabinet to feed the cable:
2. Took a 3/8" x 1/2" rubber grommet and feed it over (with much difficulty) the RJ11 connector at the end of the head end unit cable. (You can get an assortment of 125 rubber grommets on eBay as a kit labeled ATD-362. I think ATD is the company).
3. Inserted the grommet into the hole in my cabinet and feed the cable all the way into the cabinet.
4. drilled two pilot holes (3/32") and screwed in the head end display on to the cabinet. Here is the finished product:
