To start cleaning your printer, open it up and inspect for dust buildup around the toner cartridge, print drum, fuser assembly and transfer roller. Using either a vacuum hose attachment or a small paint brush gently remove any visible dust from these areas. Be careful not to touch any of the internal components with your fingers as this can cause damage.
Then, use compressed air to blow away any residual dust particles from hard-to-reach areas such as inside the paper feeder path and under control boards. Finally, clean off the exterior of the laser printer with a soft damp cloth and gentle detergent solution - be sure not to use abrasive chemicals as they might cause damage.