software downgrade to 4.1.2

[Majzikj]

I would like to downgrade my Sony SP because the newest 4.3 version of Android it really sux!!!! It crashes 5-10 times a day. How can I to downgrade it? 

[Uliwooly]

before you do so, re-install the latest update with SUS 

Update Service (SUS)

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

[Uliwooly]

as far as downgrade, you have 2 options

either Sony xperia care

or 

flashtool