There is nothing difficult about removing it. My Ford CD states to disconnect the battery for a minimum of 1 minute before disconnecting the air-bag. I just removed my driver's side one yesterday after removing my battery cable for barely 5 minutes. No sudden explosions occured. If it makes you feel safer go with 30 minutes. Here is the procedure:
Passenger's Side
REMOVAL
Remove the battery cables.
1 Remove the battery ground cable.
2 Remove the battery to starter relay cable and wait one minute for the backup power supply to be depleted.
NOTE: When the battery is disconnected and reconnected, some abnormal drive symptoms may occur while the vehicle relearns its adaptive strategy. The vehicle may need to be driven 16 km (10 mi) or more to relearn the strategy.
3 Open the glove compartment door to access the mounting screws.
4 Remove the two screws.
5 Pull out the passenger side air bag.
6 Disconnect the electrical connector.
If the passenger side air bag module is diagnosed as faulty, dispose of the air bag.
INSTALLATION
To install, reverse the removal procedure.