How do you disconnect airbag?

Warning: this answer is given for "most" systems, but may not work with all and could result in a small (and expensive) explosion. It is strongly suggested you get a repair manual for your year, make, and model of car.

In most systems you disconnect the NEGATIVE battery cable (at the battery post) and touch it to the POSITIVE battery post, then using a low pressure clamp; clamp the cable to the post for the entire time you are working on the system. If you disconnect the wiring for the air bag you MUST connect the two wires together (with a jumper wire) to ensure no static discharge sets off the explosive.

Second Warning: The above information cannot be used to operate the vehicle with the air-bag disconnected for any length of time; the car may not run with the air-bag disconnected and its disconnection results in a serious danger to the occupants (more so if it is left in the car but disconnected, as any form of static or EMP discharge can set off the unit and injure occupants)