Hello Maurizio,
Thanks for your interest in upgrading!
Sorry to say that our upgrade paths actually don't work with your upgrade plans, you can only upgrade the whole Woodwinds I to the Full Library. This is because with our upgrade paths we (correctly!) expected that most users want to upgrade from single instruments to a collection, not from a collection to single instruments Full Library.
I also see when you made your purchase in March 2018 we already made an exception for you and exchanged your single instrumetns to the Woodwinds I collection. Maybe it's better to discuss this very special case in our support? Please contact our sales department, best with details on which instruments you want to upgrade, and I'll be happy to see what we can do.
Best,
Stefan