To have italian on your phone and other european languages, IMO flashing is the best way.
So firstly you will need a program to flash the phone, XS++ is most recomended, Here tutorial:
XS++ 3.1 Guide-Flashing,Customizing,Recovering - Top Sony Forums
Next look at the language package you want:
Top Sony - Languages Description
which I guess is EUROPE_5
Next you need to download the firmwire:
Downloads - K770 - Top Sony Forums
You will need the MAIN, FS and also need the custom pack, from here:
Downloads - k770custpack - Top Sony Forums




