Ciao! Enzo,
Sadly you'll need to bring your system into an Apple Store as you do need a replacement display assembly which is covered under warranty.
Don't try to clean this your self as the cover glass and the LCD are fused together and can't be separated. Besides taking the display off alone here is a big job and you need to be very careful as you can easily damage it just in the process of taking it off.
What part of Italy are located? I'm planning on retiring their in a few years.