There is no real good way of making a trailer out of them. The third member needs to stay in there because the axles center themselves in the side gears. I have seen people torch the torque tube and take the u-joint out and weld something over where they torched it. Your gears will be running all the time. As cheap as axles are these days, I would get rid of the torque tube and put a trailer axle in its place.