Detach all of the motherboard's circuit plugs. Keep note of where each plug attaches for installation of the new one.

Lift the main board up and replace it with a new functional one. Make sure the replacement main board lies flat on top of the screw posts inside bObsweep.

Re-install the 3 screws you removed in the previous step.

All the circuit plugs you removed in the first step must be reconnected in the correct spaces.