1. Make sure the vehicle is parked and the engine is off.
2. Locate the airbag deactivation switch. In the Citroën Berlingo, it is usually located on the side of the dashboard, near the driver's seat. It may be labeled "Airbag" or "SRS" (Supplemental Restraint System).
3. Press the airbag deactivation switch and hold it for a few seconds. The airbag indicator light on the dashboard should illuminate to indicate that the airbag is now deactivated.
4. To reactivate the airbag, simply press the airbag deactivation switch again. The airbag indicator light should turn off, indicating that the airbag is now active.
Please note: Deactivating the driver's side airbag should only be done if absolutely necessary, such as when transporting a rear-facing child seat in the front passenger seat. Refer to your vehicle's owner's manual for more information and safety precautions.