Make sure the laser is unplugged before removing any cover. A good Shop Vac is useful in this process. Besides vacuuming under the laser table for debris, the air ducts inside the laser and from the back need to be brushed to loosen the built-up particles. I use several types and sizes of brushes. The two most useful brushes are a bottle brush and dryer vent cleaning brush.
Remove the laser sides and back and vacuum everything. I also remove the ducting from my exhaust and clean it thoroughly. Brush and vacuum every place that debris gets lodged. Since I use a motorized filter system, I take it apart and vacuum and wipe it down. If you use an exhaust blower, give it a good wipe down and vacuum it. This may make the motor bearings last a little longer.
-Bob Hagel, Eagle’s Mark