STEP TWO: How to remove a car battery

Check the owner's manual for special instructions. Before removing the old battery, carefully note the location of the positive battery terminal and mark the polarity on the positive cable. By doing this, you will avoid installing the new battery reversed.

Read the Safety & Handling Information

Remove the ground cable connector first. This precaution will avoid damage to wiring, and/or the battery, by accidental grounds with tools.
Use the proper size box, or open-end wrench when removing battery cables.
Inspect the battery tray for possible damage or corrosion. Be sure that the tray and hold-down are mechanically sound and free of corrosion. Corroded parts may be cleaned with water (to which some household ammonia or baking soda has been added) and scrubbed with a stiff brush. Cleaned parts should be dried and painted. Do not paint battery terminals.
Clean and tighten the ground connection. Tighten starter relay and starter connections too.