Unless you are trying to resolve a print quality defect (or a toner spill), don't bother.
Toner & paper dust is normal & perfectly OK inside a laser printer (especially high volume printers), they do not generally need cleaning (as long as you replace the consumables at the appropriate times).
If you absolutely must (oc much?), get a toner cloth & follow the instructions that come with it. A slightly damp lint free cloth will work as a substitute, but a toner cloth is the proper tool for the job.
Viper GTS