If your vehicle is newer then you first have to get a tool to keep the settings of the radio and various sensors connected to the PCM before you undo the battery's hold down bolts then remove the clamps holding the battery cable to the posts then the battery can be removed. When reinstalling the battery you first have to reconnect the cables then secure the battery's hold down bolts before removing the tool that kept the settings.

Depends on the car. On my 2000LHS you have to remove the front tire and inner front fender well. Then remove the battery terminals cables, battery hold down and remove battery through fender. Most cars you can skip the wheel and fender part and do it all from under the hood.

Remove anything that is covering battery.

Disconnect (-) cable first

Next disconnect (+) cable

Unbolt and remove hold down

Pull out battery.

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