Empty any water from the glass bowl.

Unplug the mist-making unit from the transformer. Remove the mist-making unit from the glass bowl and allow it to dry completely.

Using the special tool, unscrew (counter-clockwise) the threaded ring on the top of the mist-making unit.

Remove the old ultrasonic disc. Occassionally, the rubber sealing washer will come out with the old disc. If this happens, be sure to place it back in the bottom of the mist cavity before proceeding.

Place the new ultrasonic disc TOP SIDE (the white or silver colored side) UP in the mist cavity in the mist making unit.

Screw the threaded ring back in place on the top of the mist-making unit (clockwise).

Replace the mist-making unit in the glass bowl. Thread the cord through the hole and push the rubber plug firmly into the hole to seal it. Refill the glass bowl and plug the cord from the mist-making unit back into the cord on the transformer.