I don't think you're going to have to use the button. My screenshot is of the 9960 on the left and 9140 on the right. I don't know if the diagram is bad or if you got a different cable, but look at the "accessory cable". Yours just shows 2 relay wires and mine had the camera control terminal.
You might just need that cable.
I'd also suggest that you check on kenwoodforums.com. It is very active and has a crapload of useful information. It's not your typical "manufacturer's forum" IMO.
