How much? and Easy to use?

[Top Sony]

Just buy a log (6 Euros) and flash your phone in simplest and fatest way.
See my signature.
Regards!

[Keithod]

I done it Wotan before. I'd recommend them! It's as simple as opening the client application, enter your login details, press start (it will detect your phone CID), choose W610 instead of K550 and then choose appropriate firmware (or leave as the default!) and press flash! ~15 mins later you will have a a phone with nice flash menus and all the bells and whistles! For customisation choose a generic CDA!

:)