Fluorescent Light Fixture Diffuser
Place a ladder beneath the fluorescent light fixture. Turn the fluorescent light off. Let the fluorescent tube in the fixture cool for an hour before continuing.
Measure the length and width of the fixture, using a tape measure. Purchase a piece of plastic diffusion material that matches the measurements; if no piece matches the measurements, purchase a piece that comes close to matching and then cut the excess off using a utility knife.
Drill a hole one inch in from each end of the plastic diffusion material, using a power drill.
Hold the material against the light fixture, over the tube. Make a dot on the fixture through the two holes, using a pencil. Remove the material from the fixture.
Drill a hole in each of the dots with the power drill. Place the material back over the fixture. Screw metal screws through the material and into the fixture, using a Phillips screwdriver.
Move the ladder away. Turn the fluorescent light on to enjoy the diffused light now being emitted by the fluorescent light.
Fluorescent Diffuser Panel
Place a ladder beneath the drop ceiling that houses the fluorescent light fixture. Measure the length and width of the panel that is over the fixture, using a tape measure.
Purchase, at a hardware store, a drop-ceiling diffuser panel that matches the dimensions of the drop ceiling panel. If the size is unusual, have the hardware store cut a diffuser panel to size for you.
Lift up on one end of the drop ceiling panel that is over the fluorescent fixture. Slide the panel off the beam in the drop ceiling it is lying on. Slide the other side of the panel off the beam it is lying on. Place the panel away for safekeeping.
Slide one end of the diffuser panel on top of the beam on one side of the hole in the drop ceiling. Slide the other end of the diffuser panel on top of the beam at the other side of the hole.
Adjust the panel so that it is covering the hole. Move the ladder away. Turn on the fluorescent light to enjoy the diffused illumination.