Using a Philips head screwdriver, open the drain and the coolant will begin to run out slowly. You may want to put the car on ramps or jack it up since most catch basins, once in place, leave little room for you to open the drain.
They bend like aluminum foil and damaged fins will reduce the cooling ability of your radiator. If you plan to reinstall your radiator, you must be very careful not to damage the cooling fins. While not mandatory, the job will be easier if you raise the front of the car using ramps or jack stands. Like everything else under the hood, it looks a little daunting at first, but radiator replacement is really a fairly easy job that requires no special tools. Whether your radiator is corroded and leaking, or you're changing your timing belt and need some extra work space, you may need to pull your radiator from your Miata.
