Re: Replacing drive shafts - diy or garage?
Don't know for sure, but think you don't have to undo the hub nut. They are done up really tight though. Even with a large breaker bar and standing on the other end, it is a challenge!
I believe you will have to move the hub out of the way to some extent to gain access, track rod, suspension lower, lower swivel disconnected.
Undo outer CV joint halves. Don't know here how the joint is removed from the drive shaft on a 156, Fiats have a circlip on the shaft (undo boot clip and they slid off) That allows access to inner boot, shaft still in place.
If the shaft has to come out, it is held in by a bearing and it's retainer part way along the shaft. To undo the retainer, undo the three 6m bolts, screwed into the triangular bracket and knock the drive shaft outwards. (not difficult)
Sorry can't help on CV to shaft retention, perhaps someone else knows?