How do I change the switches in the steering wheel on a 2006 GMC 2500HD sierra?

This is something that would be best done by the dealer due to the airbag being in the steering wheel , that being said if you wish to attack this on your own still you have to unplug any power [battery, back up battery, stereo amps stiffening capacitors etc] then there are some small screws on the back of the steering wheel that need to come out before the horn/airbag assembly will come out to allow you to disconnect and replace the steering wheel switches depending on the accessories on your truck you may also need to remove the steering column covers before you can acess the scews in the back of the steeringwheel. be VERY cautious of the airbag connectors and wires but you would still be safer and better off letting a dealer change those out for you.