Get a
2.2ohm fused resistor* and a couple of links from a small
chocolate block connector.
Disconnect battery for at least 20 mins as airbag system can detonate for a while after battery power is cut.
Disconnect airbag and connect resistor in place of the airbag in the circuit. Insulate wire and connector block well with insulating tape.
Reconnect battery.
Done (probably).
You could also solder the resisitor in and insulate with shrink-tube for a more professional, permenant fix or get a spare of the existing connector and build a deletion connector with the resistor in it if you will want to disconnect/reconnect often.
If you don't do it right (bad connection to resistor) the system will register a fault and you will have to try again from scratch and then clear the error with a secret sequence that involves fiddling with turning the ignition on, then off, then on pressing pedals in a special order, winding the windows up and down, hopping clockwise three times humming the theme tune from The Wombles backwards, sacrificing three cross-eyed virgins on midwinter's eve and so on.. (or something like that anyway.. just search, it's been covered recently).
Airbags are explosive devices and should be treated as such. You can't treat them roughly or just bung them in a skip. They have to be handled and decomissioned/disposed of correctly.Scrappy or garage should be able to do that. They will detonate it safely.
This method *should* work for most airbags.
All advice at your own risk and with no liability accepted
Edit: Ed says the airbag in question needs a 2.7ohm resistor and he's the N16 guru.