Let the engine cool completely
Park on a level surface
Open the hood
Place a drain pan under the radiator drain plug or lower hose
Remove the radiator cap only if the engine is cool
Open the drain plug or disconnect the lower radiator hose
Drain the old coolant into the pan
Close the drain plug or reconnect the hose
Fill the radiator with the correct coolant mixture
Fill the coolant reservoir to the proper level
Start the engine with the heater on
Let the engine run until it reaches operating temperature
Check for air bubbles and add coolant as needed
Replace the radiator cap
Check for leaks
Recheck coolant level after the engine cools again