Swapped mine some time ago for the same reason -
Centre the steering wheel straight ahead
Disconnect the battery
Wait at least half an hour - seriously, I waited an hour to be sure for the current to die out of the airbag system.
Remove the 2 allen screws the are round the back or the steering wheel, coming forward into the airbag centre section. (put your hands on the 3 and 9 o'clock 'spokes', extend your index fingers and they'll find the recesses the allen screws are in)
Ease forward the centre section of the wheel as it's free now
Twist and remove the airbag charge covering the centre steering wheel nut - note which way was up before removing (mark with a cd marker?)
Place this removed 'canister' somewhere dry and safe as this has to go back on...
Remove the centre steering wheel nut
Pull off the steering wheel, some wiggling may be required to slacken.
Put your 'new' wheel back on ensuring straight ahead and reverse all of the above to refit and replace everything.
Concerned as I was when I removed the airbag charge I was sat in the passenger seat and reached across, just in case it went bang.... no need as it happened. Big thing is to wait the reqired time with the battery disconnected to let the charge out of the airbag system before exploring!