Cleaning cliff sensors on an iRobot Roomba 500 or 600 series.

How to actually clean the cliff sensors on an iRobot Roomba 500 or 600 series. iRobot's video demonstrating the process only shows how to clean the outside of the sensors. This video demonstrates how to clean the inside of the sensors.
1. Remove dust bin.
2. Remove battery cover (4 screws).
3. Remove battey.
4. Remove bumper trim (8 or 10 screws).
5. Pry sensor from the body of the Roomba using a flat head screwdriver.
6. Carefully separate the clear portion of the sensor from the black portion of the sensor.
7. Wash and dry the clear portion of the sensor with a cotton swab.
8. Blow dust out of the black portion of the sensor.
9. Reinstall the sensor (excessive force may be required).
10. Wiggle the sensor to ensure it has snapped into place fully.
11. Repeat for other sensors.
12. Reassemble the Roomba.