For an at-home flush, buy some cooling system flushing solution at the auto parts store and follow the directions on the bottle. Usually you'll want to drain the coolant, pour the flush in, fill the the radiator with water, and run the car for 5-10mins(or until it's hot, while parked, of course) with the heater blasting full-hot. Then you drain, fill with water, and run the car again, then drain, and refill with fresh coolant/distilled water mixture. If you want some extra cooling capacity, run a bottle of Redline Water Wetter. It's about $3-4 a bottle and increases the coolant solution's ability to dissipate heat. One bottle will treat your entire cooling system. Water Wetter also lubricates the seals in your cooling system and helps prevent corrosion.