It's pretty straight-forward but a hassle:
http://www.fiatboo.co.uk/photogal/guidepics/Stalkunitremoval.pdf
After you loosen the 24mm nut holding the steering wheel on, don't take it all the way off. It will keep you from hitting yourself in the face with the steering wheel when you yank it real hard to get it off. Don't ask me how I know this...
That guy also made a nice guide to fixing a busted stalk:
http://www.fiatboo.co.uk/photogal/guidepics/stalkrepair.pdf
So if you have the time, maybe try that first to potentially save 60. But if it doesn't work you'll have to pull it all apart again. I think I didn't try that last time because it was also winter time and I didn't feel like freezing my a** off more than I needed to.