see the little V shaped legs?
they sit on top of the radiator
then you hook the chain up to the choke lever (be sure to read your manual to see how many links you need, it varies between cars and depending on engine/transmission)
the little black line (barely visible in the picture) should be on the bottom of red
turn on the car and let it idle for 5 minutes
IF the choke mechanism is operating as it should, the black line should now be on the green (or still yellow on the pre 67 A bodies with shorter throttle cables)
(this is a total load of course, I have no idea what it is)