Owner's Manual
Page 271
... tighten the plug. At this point, wait until the engine reaches normal operating temperature; M Changing Coolant (With Rear Heater) Have an Authorized Mazda Dealer change coolant 4. WARNING Removing the Cooling System Cap: Removing the cooling system cap while the engine is gone, press down on the cap...the used coolant. 3. Install the cooling system cap. Run the engine at idle with running or hot is cool, remove the radiator drain plug and drain the coolant into a suitable container. Step back while the pressure escapes. This might lead to provide freezing and corrosion protection...
... tighten the plug. At this point, wait until the engine reaches normal operating temperature; M Changing Coolant (With Rear Heater) Have an Authorized Mazda Dealer change coolant 4. WARNING Removing the Cooling System Cap: Removing the cooling system cap while the engine is gone, press down on the cap...the used coolant. 3. Install the cooling system cap. Run the engine at idle with running or hot is cool, remove the radiator drain plug and drain the coolant into a suitable container. Step back while the pressure escapes. This might lead to provide freezing and corrosion protection...