Depends on how thoroughly you want it cleaned. If you want it looking brand new Id do a complete tear down and clean every piece as you go. If you just wanna get it 85% clean the Aliens suggestion works fairly well for the spot you can get to without taking it apart and that arent near electronics. You can also use CowRCs Moo-tor cleaner and compressed air (may need some use of a tooth brush) or denatured alcohol and compressed air (again may require some use of a tooth brush). Both of the last two options are electronics safe.
If its been quite awhile since youve done a complete teardown and cleaning of your kit or if youve never done it I would highly recommend doing it periodically so you can make sure all of your bearings are good and you can also check for cracked or broken pieces, missing screws, and any other problem areas you may have.