If you are unsure about any step, take your vehicle to a qualified mechanic. Airbag deployment is incredibly powerful and potentially lethal if the system is tampered with incorrectly.
That said, here's a general outline of the process. These steps are general and might not be exactly accurate for your specific truck model. Consult your owner's manual or a repair manual specific to your 1997 Chevy truck for precise instructions and diagrams.
1. Disconnect the battery's negative terminal. This is crucial to prevent accidental airbag deployment. Wait for at least 30 seconds to allow the system to fully discharge.
2. Locate the passenger airbag switch. This is usually located on the dashboard, near the passenger side glove compartment. The exact location varies by trim level.
3. Remove any access panels or trim pieces. This might involve removing the glove compartment or some surrounding trim to expose the switch.
4. Disconnect the electrical connector. This connector is usually a simple plug-in type. Carefully unclip or unplug it. Take a picture or make a note of how it's connected before disconnecting to aid reassembly.
5. Secure the connector. Once disconnected, you might want to tape it up to prevent accidental reconnection.
Re-installation is the reverse of the above steps. Remember to reconnect the battery's negative terminal after re-installing the switch and its connector.
Again, I strongly urge you to seek professional assistance if you are not confident in your abilities. Airbag systems are complex and potentially lethal if mishandled. Incorrectly disabling the passenger airbag could have serious consequences in a collision.