How to change batteries in bmw x3 key fob?

To change the batteries in a BMW X3 key fob, first, locate the small notch on the side of the fob and use a flathead screwdriver or a coin to gently pry it open. Once the fob is separated, remove the old battery, typically a CR2450 or similar, and replace it with a new one, ensuring the positive side faces up. Reassemble the fob by snapping it back together until it clicks securely. Finally, test the key fob to ensure it functions properly.