 To replace the batteries, first you'll need to remove the battery pack cover. Make sure that the battery pack cover lock is in the unlocked position. The battery pack is unlocked when the notch is in a vertical position. If it is not in the unlocked position, use the screwdriver provided with your sonnet kit to turn the lock counter-clockwise to the unlocked position. Be careful not to use too much force when you turn the lock. Pull back and completely remove the battery pack cover. Remove the batteries from the battery pack frame by using the magnet of the coil. Insert the batteries into the battery pack frame with the positive poles facing out. Slide the battery pack cover over the battery pack frame and be careful not to use excessive force. The air inlets of the battery pack cover should be on the same side as the coil cable socket of the control unit. Sonet is now ready to use. Place sonet behind your ear and place the coil over your implant.