What specifically do you need cleaning and why?
If there's no dust visible on the sensor & your focusing screen is clean, I'd advise NOT cleaning it for the sake of it. No sense in needlessly fiddling with it.
For lenses, you can safely clean the front/rear elements with a soft cloth yourself. Otherwise, what kind of dirt/contamination are you seeing?
Ideally images showing the dirt would help, but simply cleaning it because you haven't used it for a while isn't usually necessary.