Straight from the dealer protion of HMA Service (std practice with most any other maker) --
Please read the following precautions carefully before performing the airbag system service. Observe the instructions described in this manual, or the airbags could accidentally deploy and cause damage or injuries.
• Except when performing electrical inspections, always turn the ignition switch OFF and disconnect the negative cable from the battery, and wait at least three minutes before beginning work.
The contents in the memory is not erased even if the ignition switch is turned OFF or the battery cables are disconnected from the battery.
• Use the replacement parts which are manufactured to the same standards as the original parts and quality.
Do not install used SRS parts from another vehicle.
Use only new parts when making SRS repairs.
• Carefully inspect any SRS part before you install it.
Do not install any part that shows signs of being dropped or improperly handled, such as dents, cracks or deformation.
• Never perform electrical inspections to the airbags, such as measuring resistance.
• Do not position yourself in front of the airbag assembly during removal, inspection, or replacement.
• Refer to the scrapping procedures for disposal of the damaged airbag.
• Be careful not to bump or impact the SRS unit or the side impact sensors whenever the ignition switch is ON, or at wait least for three minutes after the ignition switch is turned OFF before begin work.
• During installation or replacement, be careful not to bump (by impact wrench, hammer, etc.) the area around the SRS unit and the side impact sensor. The airbags could accidentally deploy and cause damage or injury.
• After a collision in which the airbags were deployed, replace the front airbags and the SRS unit. After a collision in which the side airbag was deployed, replace the side air bag and side impact sensor on the side where the side airbag deployed and the SRS unit. After a collision in which the airbags or the side air bags did not deploy, inspect for any damage or any deformation on the SRS unit and the side impact sensors. If there is any damage, replace the SRS unit and/or the side impact sensors.