Turn off the breaker that controls the kitchen lights.
Remove the cover from the fluorescent light fixture and remove the fluorescent tubes from the fixture.
Find the screw that secures the wiring cover onto the light fixture and remove it with a screwdriver. Pull the wires down and out of the light fixture.
Remove the wire nuts from each of the three wires and separate the wires. In some cases, the green or bare wire extending form the ceiling will bolt to the housing of the light fixture. Remove the bolt with a screwdriver.
Remove the screws that secure the light fixture to the ceiling or wall and discard the old fixture.
Place the new fixture onto the wall and secure it with the screws supplied with the fixture.
Connect the two black wires together with a wire nut, connect the two white wires together with a wire nut and connect the green or bare wires with a wire nut. Again, in some cases, the green or bare wire extending from the ceiling secures to a green bolt on the fixture. If this is the case, secure the wire to the bolt with the screwdriver.
Tuck the wires into the fixture and secure the cover in place.
Install the fluorescent tubes and place the cover onto the fixture. Restore power to the fixture via the breaker box.