I think connectors 2 & 3 unplug relatively easily; one needs to carefully use a pointed (not sharp) tool. try to wedge-in the edge of the tool right between the circuit board and the cables (of the 3- or 4-cabled connector), then just try to use the tool as a lever to pop the connector off the plastic plug.

NO need to use brute force - ONLY gentle moves are required :)