The flash capacitors connected to the yellow wire harness have dangerous amounts of stored charge. You must safely discharge them before continuing. Use a Capacitor Discharging Tool to do so.

Grasp the motherboard from the sides and lift it up. It is still connected by two wires on the bottom right side.

Pull the wire ribbon on the underside off with tweezers.

After you have discharged the capacitor, pull the yellow wire harness out using tweezers.