As mentioned above, the airbag just stays attached to the dash. If you need to swap it to the replacement dash, it will be quite easy with both dashes out of the car.
The first time I removed a V8 dash it took about an hour to get out, and about the same to re-install.
Now that I know where everything is that needs to be disconnected/removed/unbolted, I can have it out in about 35-40 mins, and about 45-50 going back together.
TIP: Get some moving blankets to put on the ground to place the 'good' dash on, and take the extra 2 minutes and REMOVE THE SHIFTER all together. The first dash I did, the glove box door got scraped on the edge of the shifter going back in, and on the second one it was a close call. Now I just pull the shifter.