When handling an air bag, never touch any exposed terminal pins on the back, put a small piece of black insulation tape over them(if it is that type)static in your fingers could set them off.
When carrying an air bag always carry it close to your chest with the base your side and the bag facing out/forward.
When you have removed air bag it should be stored in a lockable steel box or cage, obviously you will not have one to hand so put it in boot base down/face up.
As someone else has said disconnect battery.
when you have refitted air bag, close all doors and windows, switch on ignition, then reconnect battery, so if it goes off it is not in your face.
It may bring on the air bag warning light which the dealer will probably have to reset.
Never ever do any testing of the air bag electrical system with a air bag in place and connected, disconnect them and use a suitable resistor to simulate air bag.
I used to service and repair air bag systems as part of my job and i have seen some horrific videos/pictures of people not adhering to those rules.