Step 1: Clean your teeth to remove any excess plaque and food.Step 2: Unscrew the top off the syringe.Step 3: Apply HALF of a syringe, 2.5ml, to each tray at the front side.Step 4: Put the device in your mouth and switch it on to start the 20 minute treatment. (Will switch off automatically).Step 5: Rinse with water and recharge in either the charging base or attached to the USB charging cord after each use.Step 6: Repeat steps daily for 6 days to complete a full treatment.Expert Advice: When applying the whitening gel to the device, face the shield upwards, so no gel is spilt.