It’s been quite awhile since I opened my CHUCK, to replace the camera, but it is fairly straight forward. You’ll first need to remove the two antenna connections, servo leads, and the bolts securing the CHUCK to the airframe. Once done the CHUCK and camera assembly should just slide out.
The next bit isn’t obvious but you’ll need to carefully peel the top cover off the CHUCK to get access to the screws that hold the case together. Once the screws are removed the case should separate and you’ll have access to the PCB. Be careful from here as there are some very small connectors and the odd ribbon cable you will not want to damage.
If you’re new to working with this stuff I recommend doing it in stages with a break in between each stage. Damage is usually caused by rushing and getting frustrated, I know of what I speak :-(
I’m not aware of any videos on how to do this but I have found a Blog on DIYDRONES detailing much of the teardown.
Parrot Disco Teardown