How do I flush the water filter after installation?

Flush 1 gallon of water through the filter before drinking or using water from the refrigerator, which takes approximately 6 minutes. To flush, press a large glass or cup against the water dispenser lever, fill the glass, empty it into the sink, and repeat. Run water through the dispenser until the water runs clear (approximately 6 to 7 minutes) to clean the water supply system and remove air from the lines. (Page 10, 13)