Although the camera is sealed, its exposed each time you change the lens. Hence it is important to avoid doing it in dusty environment. If unaviodable, point the camera downwards when changing lenses. And unless you are quite savvy in removal of dfelicate components, I suggest to leave it alone and get Kelvin from Emjay to help you clean it when you have the opportunity. A friend of mine tried to do this with his brand new Canon camera and it ended up back at the service centre for realignment!