You don't need to disconnect the batt for a while. Here's how to remove the airbag safely:

1. Disconnect negative battery cable

2. Underneath front passenger's floormat, there's a "trap door". Underneath, there is a red wiring harness. Unplug it.

3. Remove airbag from steering wheel. There are two Torx fasteners on the rear left and right of the steering wheel, but a 4mm allen wrench will also work.