You might think the only thing that needs cleaning on your rear projection TV is the front screen. Other components can get dirty and affect the picture quality. These components need to be cleaned, as well; albeit, very, very carefully.
Unplug the TV from the power supply prior to any cleaning.
Clean the front screen by spraying glass cleaner onto a cloth and gently wiping the screen. Do not spray cleaner directly onto the screen. The liquid can run down the screen and behind the frame that holds it in place. You can damage electronic components or cause the chipboard/fiberboard frame to swell and warp.
Remove all cables and wires from the rear of the TV. Remove the fiberboard cover from the back of the TV. When you remove the fiberboard cover, you will probably notice the main electronic circuit boards covered in a thick layer of dust. Do not clean these components yet; you want to work from the top down.
Look above the main electronic circuit boards. You should be able to see the mirror used to reflect the image from the color guns to the front screen. If there is a horizontal fiberboard cover that hides the mirror from view, remove it now.
Use the static duster to gently clean the mirror. Blast any remaining dust with compressed air. Avoid using glass cleaner as you'll probably leave streaks on the mirror. (It's not like anyone has had their fingers on the mirror since you bought the TV ... you are just trying to remove dust.)
Look to the front of the TV, behind the main electronic circuit boards, and clean the three glass lenses on top of the color guns with the static duster.
Gently clean the main electronic circuit boards with the duster, soft bristled brush, compressed air and vacuum cleaner wand. Be careful not to disconnect any wiring or hit the electronic components.
Replace the fiberboard(s). Plug your components back into the back of your projection TV. Plug your TV back into the outlet and turn it on to make sure your picture is improved since the cleaning.
Things You'll Need
If you feel your mirror is still dirty you can use glass cleaner on it; it should not be necessary, however.