CG02 Strange blurred and milky area on my videos

Today i flew with my Chroma equipped with CG02+ camera, on the ST10 screen i saw a strange blurred area, seems to be like the lens would be partially tarnished .
After landing i check the lens, it seems to be clean, also inside the protection glass there were no any sign of humidity or something else.
This area is recorded on the videos and pictures, and never happens before.
Could it be humidity on the sensor??
It's more visible if you turn the camera to the light, i.e. to the sun or luminuous lights.
Does somebody have an idea how to open the camera to clean lenses and sensor?
At the moment i,ve put the camera in a box with some bags of silica gel, will check situation next weekend.
Thanks for your suggestions

 

Self answer: I've found this video, I post the link 'cause it's very interesting and could be helpful for somebody else.
It's for the CG03 but is the same procedure for CG02.

 

I resume this post because despite trying to clean the camera lens in the best possible way, the whitish reflection remains visible.

It would almost seem that the lens had a defect, but looking at it you can not see any anomaly.
By shading the shot with one hand the defect disappears.
I saw videos from last year, the flaw wasn't there.
Does anyone have any idea how to so lve it?

 

I found the problem: looking at the lens with a magnifier and illuminating it with a led light, I saw a micro crack on the internal lens! I don't know how it can be happened, cam never had bumps or falls!
I found on this forum an Italian guy who was selling a CG02+ camera with broken gimbal for about 50$, so I bought it and replace the whole optic, now it's back perfect.
I've removed the broken lens from the old cam, and I'm now looking for a spare or adaptable new lens in order to repair the old cam.