Cut power at the fuse box. Climb a ladder under the ceiling fixture. Loosen the fixture from the ceiling by unscrewing the mounting screws that hold it there, pulling it down to expose the wiring. Disconnect the fixture wires from the house wires and pull the fixture free.
Take the mounting bracket from your fan kit up the ladder. Mount it to the electrical box using the provided mounting screws. Make sure the wires from the electrical box are hanging freely down from the ceiling
Bring the fan motor housing up the ladder. If there's a mounting hook on your mounting bracket, hang the fan motor from it so you can wire the fan; otherwise, set the fan on the top of the ladder as close to the ceiling as you can get it.
Connect the wires coming out of the fan house to the same colored wires coming out of the electrical box, connecting black to black and white to white. Connect them by lining up the two bare wire ends next to each other, pointing in the same direction, and twisting a wire nut over both of them at once, then wrapping electrical tape around the connection.
Find the copper grounding from the electrical box. Twist the wire around the green grounding screw in the fan house. Tighten the screw.
Hold the fan motor housing up to the mounting bracket, tucking the wiring up into the box as you go. Secure the housing to the bracket using the provided screws.
Bring the fan blades up the ladder and mount them on the motor according to the instructions. Turn the power back on and test the fan.