How do you reset the increased emission light on 2004 525i BMW?

To reset the increased emission light on a 2004 BMW 525i, you typically need to use an OBD-II scanner to clear the diagnostic trouble codes (DTCs). Alternatively, you can disconnect the battery for about 15 minutes, then reconnect it, which may also reset the light. However, it’s essential to first address any underlying issues that triggered the warning light before resetting it. Always consult your owner's manual or a professional if you're unsure.