The mast can be replaced if he has a good motor unit. The entire mast can be easily removed by unscrewing the finial, and prying the rubber mounts out of the motor unit. You can then slip the entire mast unit off of the cable/top section. If the cable is broken, and the donor unit has a good cable, it can be transferred as well, but you will have to disassemble the motor unit. There are also cables available.