1. Remove both outer and inner lids. 2. Add water until level reaches, but does not exceed, the red water fill line marker. 3. Add 5-8 drops of essential oil. 4. Replace both lids back onto the unit; align the groove on the outer lid to the notch on the base. 5. Plug the power adaptor into a power outlet. 6. Press the on/off button to switch on. 7. The unit should be producing mist and the LED light should be on.