This is great link!
Thank you, I was desperately looking for a Fiat dealer able to do it, or a DIY to do it myself, and didn't find any until now.
I own a Fiat 500c from 2010 (ivory body and red soft roof), and same issue, the laquer on the red spoiler is going away, making the spoiler to look really bad.
I bought a spare spoiler but didn't know how to remove the inner roof lining. It looks very easy according to the DIY. I will try myself!
So after changing it it means I will have a spare spoiler. I will come back here after doing the change myself.
Cheers!