1. Open the hood of your BMW 525i.
2. Locate the battery. It is in the front of the engine compartment on the passenger side.
3. Disconnect the negative battery cable. This is the black cable that connects the battery to the chassis of the car. Use a wrench to loosen the nut on the negative terminal and remove the cable.
4. Disconnect the positive battery cable. This is the red cable that connects the battery to the starter motor. Use a wrench to loosen the nut on the positive terminal and remove the cable.
5. Remove the battery hold-down clamp. This is a metal clamp that holds the battery in place. Use a wrench to loosen the bolts or nuts on the hold-down clamp and remove the clamp.
6. Lift the battery out of the engine compartment. Be careful not to drop the battery, as it is heavy.
To reinstall the battery, simply follow these steps in reverse order.
