Instructions
Battle through the Lonesome Manor until you reach the Mad Doctor's laboratory.
Spray paint thinner into the red eyes of the two Bettleworx who are guarding the generators in the front of the room. This will destroy them and cause the generator doors to open, giving you direct access to the generators themselves.
Spray paint thinner to destroy the generators.
Spray paint thinner to destroy the three Beetleworx guards who are guarding the generator in the back of the room. This will cause the final generator door to open.
Destroy the last generator to defeat the Mad Doctor.