Take the bared wire, twist and put it into the molex crimp connector, such that the copper is between the inner two folding sides, and the plastic insulator is between the longer outer folding sides.
It helps to put the crimp in the crimping tool first.
Then push the wires in as I said above.
Squeeze the crimp tool and you'll see the 4 taps fold in over the copper and plastic insulator.
Then pop on the heat shrink tube and heat with a heat gun, or by running over a hot heat source, like a solder iron, or naked flame.
The heat shrink will 'shrink' to squeeze the connector.
Ensure the 'end' of the connector, the opposite end to the wire inserted, is flush with the end of the heat shrink.
Then the two connectors can be pushed onto the two connector 'spade' terminals inside the underside of the light. I recommend use of long nose plyers, as the crimps are usually tight.
There is no polarity, you can push the wires on either way and the light will work.