Just for the record (not saying yours needs replacing), I had to replace my steering column recently.
MultiECUScan/FIATECUSCAN reported "internal assembly faults" - see what errors you have and try clearing them before you decide to replace the column. It would be a good investment to get the software + ELM327 cable + adaptor A1 (or something made up to connect pin 7 to pin 9). See gendan.co.uk for complete packages of software/cable/adapters - very convenient. Software by itself is 50 Euro. Cable and adapters will set you up to solve problems on most FIAT/Alfa cars.
To replace the column, it's actually a fairly easy job (at least, you don't have to get dirty - took me a bit over an hour). You'll need a 3/8" inch hex socket (yes, really! - it's about 9.5mm) to undo the pinch bolt at the bottom universal joint. The correct size is an external Torx (E8), which I used to remove the column from the donor car, not a socket usually found in socket sets (can be bought specially, but why bother when a 3/8" fits...) Pinch bolt must be completely removed (not just loosened) before the universal joint can be lifted off (the steering shaft telescopes).
The lower-right corner of the dashboard can be removed - do this before struggling to reach the nuts holding the column up, as later you need the dashboard section out of the way to get the motor out. Take off the fusebox lid (couple of screws). It's then fairly obvious how to get the frame out of the way. I can't remember, think there was a screw near the air vent, and the end of the dashboard (which the door closes onto) must be prised off (a few clips).
Then take off the column covers. The bottom cover comes off, then there are two small screws you reach from underneath right up near the column stalks (difficult to see - pull the rubber stalk boots inside-out). I think you'll need a 2.5mm Allen key for these.
The steering wheel comes off next. Three bolts hold the airbag on, then the usual large nut to undo, and the wheel wiggles off without the need for a puller. The clock spring wiring does NOT unplug from the clock spring (even though it looks like it does) - you must unplug from the steering wheel circuit (be gentle) and then feed all the wiring through the hole in the steering wheel. That includes the two airbag connectors.
The column switch assembly is easy to remove but note that it has a steering angle sensor. This will need to be recalibrated afterwards using
MultiECUScan/FIATECUScan (that went smoothly for me). Try each Bosch ABS ECU type until you find the one that does not report "Invalid ISO code" (mine was ABS 8 VDC). Cars without VDC (ESP) don't have the steering angle sensor.
Because I used a second-hand column, it already had an ignition lock and I had the key. All I had to do was turn the key 'on' and press in a spring-loaded tang on the side of the lock, and then the barrel pulled out with the key. That meant I could pop in my key barrel without the need to chisel out the shear-headed (conical) bolts that hold the lock to the column. If the column is new, you'll need to chisel your bolts off to get the lock assembly off. Then you'll need new bolts. Maybe use standard Allen bolts and drill out the heads?
To actually remove the column, it's four 13mm nuts that secure the plate to the dashboard structure. There are two plugs to undo from the column motor. That part's quite simple
Bear in mind that 3-door and 5-door columns are officially different - I'm not sure what the difference is (angle/height?) but rumour has it they are not software compatible. My car had a 5dr column fitted as a replacement - and it wasn't working properly. Clearing the fault codes would restore correct operation until a fault occurred in any other ECU - then BAM! steering failure and no power assistance. I got tired of this happening and then one day, the fault codes wouldn't clear.
-Alex
