Turn off the Jenn Air stove. Turn off the gas supply line leading to the stove.
Lift the grates off the burners.
Twist the burners counter-clockwise until they unlock.
Lift the stove top up. Set the prop rod up to hold the stove top in place.
Remove the two screws holding the ignitor in place. Unplug the electrical wires leading to the ignitor. Remove the old ignitor.
Position the new ignitor onto the Jenn Air stove. Install the two screws holding it in place.
Plug the electrical wires into the sockets on the ignitor.
Replace the prop rod. Lower the stove top. Twist the burners clockwise to lock them into place. Replace the grates over the burners.