Turn off the main power breaker to cut all power to the switch and to the fan. The installation process will require electrical wiring that would be unsafe if the breaker is not turned off.
Remove the cover plate from the bottom of the ceiling fan by loosening and removing the screws and the plate. Some models use thumb screws; others require a screwdriver.
Disconnect the plug connecting the cover plate and remove it from the fan.
Feed the wires from the lighting kit through the hole in the cover plate. You may need to remove a center plug from the cover plate first.
Screw the lighting kit housing into the cover plate until it's very snug. Otherwise, it may vibrate.
Connect the white wire from the lighting kit to the white wire inside the cover plate. The wire may be marked "light." Twist them together and then twist a wire connector over both wires. Connect the black wire from the lighting kit to the black wire coming from the ceiling fan using the same method.
Reconnect the plug for the cover plate that you disconnected in Step 3.
Put the cover plate back in place and replace the screws to secure it in place.
Screw a light bulb into the socket. If there is a globe included with the light kit, put it in place and tighten the thumb screws on all sides to hold it securely in place. Do not over-tighten the thumb screws or you could break the glass.
Turn the main power breaker back on and test the fan and the light kit.