How to uninstall an update?

[#1]

Hello!

I have updated my Sony Ericsson Xperia Neo to Android version 2.3.4, build number 4.0.2.A.0.62. How can I uninstall this update so that I get back build number 4.0.2.A.0.42 or Android version 2.3.3 ?

I made a factory reset, but it did not turn out the way I wanted it. Pls help.

Thanks in advance.

[areeba]

Genuinely in need of help. I have Sony Xperia Z. Downloaded Android Kitkat 4.4.2 yesterday. I want to unistall this software update. Please help. I want the older version, it was Jellybean earlier on my device. Please help. Any help would be appreciated.

[vinnyg2]

I have recently up graded my Xperia T - I always use my tethering hotspot to use my ps3 + xbox. My tethering allowance never went down before but since this update it is swallowing my data. How can this be reversed