If you pay close attention to a couple of safety issues, changing your own coolant is a breeze. You should never pay someone to perform this simple task. If you plan on refilling the radiator, be sure to check individual owner's manuals for proper mixture levels for your automobile, and then head down to your local auto parts store and pick up the necessary coolant.
Ensure the radiator is cool before you start. Put your vinyl gloves on.
Spread newspaper or cloth under the radiator, then place the bucket/catch pan under the plug of the radiator. The plug is located on the underside of the radiator on the left.
Remove the hex nut, or screw plug. This will likely require a ratchet set if it is a hex nut, though a wrench may also work. The screw plug will require a large screwdriver. If your car model has a hose at the bottom of the radiator, as most vehicles do, remove this instead of the plug. Simply remove the clamps and pull the hose.
Allow the coolant to drain, giving it a bit of extra time to drip once the flow ceases. Carefully pull the bucket out. Replace the plug, tightening the hex nut firmly. If you removed the hose instead, make sure you get the clamps firmly in place to avoid leaks.
