How can i undo an update?

[Zouzaki_Sem]

I have Sony X-Peria Neo V and i just updated it to 4.0.4 ( march 4th 2013 ). But i dont like this update and some of the features i had and used are now gonne.
Is there a way i could return it to the latest update i did, but without losing stuff that are not in my SD card ( like my messages ? )

[Samuel1]

Contact your local Xperia Support for information regarding downgrading to previous updates.

http://www.sonymobile.com/global-en/support/contact-us/