To replace a car radiator, open the radiator drain plug and allow the coolant to flow into a catch basin. If the radiator does not have a drain plug, loosen the lower radiator hose to drain the coolant. Disconnect all hoses from the radiator, and remove the auxiliary belts.
Remove the engine cooling fan and radiator shroud. Place a newspaper and a catch basin below the radiator, and then remove the old radiator from the engine. Slide the new radiator gently into place to avoid damaging delicate hose necks and cooling fans. Replace the mounting hardware before reinstalling the cooling fan and radiator shroud.
Replace the thermostat, the hoses and the hose clamp if they are not in good condition. Attach the cooling hoses to their appropriate mounting necks, and be careful not over tighten them. Slide auxiliary belts over the pulleys, and adjust their tension by turning the tension adjustment bolts and nuts.
Depending on the make of your vehicle and climate, mix the replacement coolant and distilled water in the correct proportions. Pour the coolant in the appropriate fill area. Start the engine to allow the coolant to circulate, and add more if necessary. Using a wrench open the valve, to bleed air from the system. Continue the process until there are no more air bubbles bleeding from the system.