The airbag is held on with two bolts in the back of the steering wheel.Usually either Torx or Allen Key heads,you need to turn the steering wheel and have a look for their position.
.You just undo both,and gently remove the airbag.There will be a wire running it,so once you can get to it,pull the connection off of the bag.
The steering wheel is held on with a large nut in the centre,and is also tapered on to the colomn.Undo the nut a couple of turns,and pull on the wheel to loosen the taper.DON'T undo the nut completely,because if you pull on the wheel and it comes loose you'll smack yourself in the face with it.
(been there,done that
)Once it's loose,remove the nut and gently slide the wheel off,being carful not to damage any wiring that comes through the wheel.
Make sure the indicator stalk is centred)i.e the indicators aren't on),as you will break the pin that works the self cancelling.....
EDIT;The airbag is an explosive device,so treat it with repsect.Once removed,it should be stored in a safe place out of harms way.Your supposed to store then in a metal cage,but obviously not many people have those at home!.Please be careful....