hi, its pretty simple, your gonna get you a bottle of radiator flush, and follow instructions which includes draining the radiator, filling it back up with water,put the bottle of flush in, and run the car for about fifteen minutes, the drain, fill with water again, run the car for another fifteen, drain again, and fill up with the proper amount of fifty/fifty coolant. and your good, now if the radiator is really bad, your gonna want to repeat twice, with a second bottle of flush.