How do you flush a radiator on a 1991 subaru legacy?

To flush the radiator on a 1991 Subaru Legacy, first ensure the engine is cool and remove the radiator cap. Place a drain pan under the radiator and open the drain valve to let the old coolant flow out. After draining, close the valve and fill the radiator with a flushing solution or water, then run the engine for about 10-15 minutes with the heater on to circulate the fluid. Finally, drain the flushing solution, refill with fresh coolant, and check for leaks.