Disconnect the table saw's power cord from the electrical outlet.
Loosen the existing power switch's mounting screws with a screwdriver and remove it from the underside of the table. Follow the cord that connects the switch to the motor until you find the housing that covers the wire connections to the motor. Loosen the screws that hold the housing's cover plate in place and remove the plate.
Remove the three wires from their connection points on the motor, paying close attention to the color of each wire and where it connects. Pull the wire out of the housing, and set aside.
Connect the spades on the ends of the wire from the new paddle switch into the motor, making sure to connect the same color wires to each connection as when you removed the old wire. Replace the housing cover and secure it by tightening the screw.
Position the new paddle switch under the front rail of the table saw in the desired position. Mark the positions of the holes on the switch on the rail with a pencil.
Set the switch aside and drill a hole 1/8 inch in diameter through the two locations as marked by the pencil.
Re-position the switch beneath the rail and connect the switch to the rail with a pair of 1/4-inch screws.
Plug the power cord from the switch into the power outlet and turn on the switch to test the saw.