A cooling flush machine is needed to complete a cooling flush to an automobile.This machine transfers old coolant out ,flush in,& then rinse & refill with new coolant.If you want to drain & refill your cooling system the drain is on the lower corner of the radiator tank.here is some info to help :
Cooling System Draining and Filling Draining Procedure
Important: Do NOT add any engine coolant supplement sealant pellets to the cooling system. Drain and refill the engine cooling system every 5 years or 240 000 km, (150,000 mi), whichever occurs first.
Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
Important: Recover and store used coolant in a used coolant holding tank and submit the used coolant for recycling on a regular basis. Do NOT pour used coolant down the drain. Ethylene glycol antifreeze is very toxic. Disposing of ethylene glycol into the sewer system or ground water is both illegal and ecologically unsound.
If only partial cooling system draining is required, drain enough coolant to perform the procedure.
Important: Allow the coolant to drain completely.
NOTICE: When adding coolant, it is important that you use GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® coolant. If Coolant other than DEX-COOL® or HAVOLINE® DEX-COOL® is added to the system the engine coolant will require change sooner; at 50 000 km (30,000 mi) or 24 months.
Important: The air bleed valves are brass. Do NOT over-tighten the air bleed valves.
Important: If the coolant temperature indicator turns ON, turn the engine OFF immediately and allow the engine to cool. Do NOT remove the radiator cap.