Bust the judge down to private and dishonorably discharge him.
Officers cant be busted to private without their own court martial but he can be “dismissed from the Army” which for an officer is the same thing as a Dishonorable dischrage. He can also be relieved of his duties as a judge by his superiors including the Secretary of the Army, Sec of Defense and even the President. All officers serve at the pleasure of the President so he could be retired at the end of the month when all Army retirements for that month take place. That is exactly what should happen.