Gently lift the housing top, and slide it back while lifting.
You will find the whole camera module wrapped in thick cellophane. For reasons of heat dispersal and prolonged life, I would recommend disposing of it during following steps. But only if your camera is for indoor use ! Outdoor cams might benefit from the wrapping, containing the heat in the camera module, preventing condensation/corrosion.
Optional : for reassembly, some adhesive tape might come in handy to hold down the flat cables.