To Replace the Jigging Base on/off switch remove the 2 phillips head screws from either side of the on/off switch. Next cut the red wire going to the motor from the old on/off switch leaving yourself plenty of wire to splice together with the new on/off switch.   Pull out the old on/off switch and the battery contact that is wired to it.  Now strip the ends of the wire on the new on/off switch that doesn’t have the battery contact attached to it and the end of the cut red wire that is going to the motor.  You can put some small shrink wrap tubing over one of the wires if you want before you splice the wires together. Then once the wires are spliced together you can slide the shrink wrap tubing over the splice and heat it so it constricts down. If you don’t have shrink wrap tubing you can use electrical tape.  If you have both you can use both. Next push the battery contact that is attached to the new on/off switch into place and test the new splice and switch to make sure that everything works. Then you can screw the new on/off switch into place.  If you are unfamiliar with how to splice delicate wire together you might want to get a replacement motor instead of just a new on/off switch since the motor, on/off switch, and battery contacts are already wired together and there is no splicing rqequired.