How do you disconnect a car battery?

There are two types of battery cable connections. The clamp type connects to a post on the battery and is held in place by a nut and bolt which squeeze the sides of the clamp tightly around the post. Disconnect by loosening the clamp's nut and then wiggling the clamp off of the post, start with the negative cable (black one). The bolt on type (sometimes referred to as 'side terminal' type) is bolted directly to the battery. To disconnect this type, simply unbolt it and remove the cable end from the battery. Again, start with the negative (black) cable. If the goal is not removal of the battery, but disconnection of power to the vehicle for servicing, disconnection of only the negative (black) cable is sufficient.