A coax cable has an inner wire and then the braided shield and a quick and easy way is just to strip the cable back and solder or join using terminal block the Inner wire to the Orange wire and the Outer shield to the Green wire.
However, if you want to make a nicer, more robust solution, you could get one of these…
https://www.adafruit.com/product/2889
and one of these…
Then the Orange wire would go in the + screw terminal and the Green in the – screw terminal. The BNC connector would be crimped on to the coax cable and you end up with a much more longer lasting connection.