Open the junction box attached to the lighting can.
Slide the electrical cable from the ceiling into the junction box and secure it with the cable connector. This is a clip on the box which locks the cable into place to prevent it from moving.
Join the black wire from the light to the black wire from the electrical cable by placing the bare ends of the wires together and twisting them a couple of times with a pair of pliers. Place a plastic connector cap onto the wires, and twist them together several more times.
Join the white wire from the light to the white wire from the electrical cable by placing the bare ends of the wires together and twisting them a couple of times with a pair of pliers. Place a plastic connector cap onto the wires, and twist them together several more times.
Join the green wire from the light to the bare wire from the electrical cable by placing the bare ends of the wires together and twisting them a couple of times with a pair of pliers. Place a plastic connector cap onto the wires, and twist them together several more times.
Tuck the wiring into the junction box, and replace the cover.