After looking around for a guide to changing a top 156 wishbone I could not really find anything useful. I even found one how to guide from an Alfa garage but it seemed very over complicated for such a simple job.
So I thought while I was changing one I would take some pics and put a guide on here
Forgive me if something similar has been posted already, I couldn't find it
This may only work if the long wishbone mounting bolt has the nut on the spring side. If not you may have to loosen the strut to remove the bolt. When replacing the bolt if you make sure the nut is on the spring side it will make removal much easier next time.
Jack up the corner you are working on, remove the roadwheel and secure the car on an axle stand.
In the picture you can see the top wisbone.
You will see it looks impossible to remove the long top bolt on the wishbone to remove it in situ! it is about 7-8 inches long.
Remove the 4 screws holding the arch liner in place. Carefully unpeel it around the arch and it should then free up and easily pull downwards. Or if you can free the top part first it will then unpeel itself and drop down. Just be gentle and don't crack it.
Now you will see there is lots of space for the long bolt to be removed from the wishbone.
Spray some WD40 , plusgas etc on the balljoint nut and large top bolt nut.
Undo and remove the balljoint nut ( 17mm ) and using a separator pop the balljoint off. A cheaper tool for doing this is a fork which you just whack with a hammer to open it up but if you need to reuse the wishbone don't use one of these as it will split the rubber boot.
I used a seperator I have had for years, first purchased for removing track rod ends on my Sud
it worked fine on these. Only problem though is because the tightening nut is on top it is hard to swing a spanner on it up inside the arch. I think you can get them the other way around with the nut on the bottom, these would be even better for this job.
Undo and remove the the nut on the long bolt and slide the bolt back. ( 17mm on both ends )
it still won't come out enough
You will also have to remove the black cansister hanging from the inner wing ( 2 x 13mm nuts ) when you drop this out of the way the bolt has plenty of room to be removed fully.
Thats all there is to it, the top wishbone is removed
Then replace with the new wishbone.