Originally Posted by reaper61616
Can anyone tell me how to get back to stock via SEUS?
1) relock boot loader (do a search in the xperia forum - there's a link for it)
2) install stock kernal for Android 2.3.4 using flashtool
3) install an older version of the ROM than the latest available via SEUS (you may not have to do this step)
4) plug the phone in and activate SEUS. It will say your system needs to be updated - just follow the instructions.
Instead of SEUS you can also use SE PC companion - in this case you probably WILL have to use step 3 in order to allow pc companion to deterime that you are on an older ROM than is available on Sony's website.
Note: if you dont unlock the loader, SEUS (and PC Companion) will download the ROM from Sony's website but then come up with an error saying the software can not be installed - i cant remember the exact errror but the reason it fails is because it has detected a problem with the bootloader (e.g. it is still un locked)