Originally Posted by BarajaVLC
Does anyone know where I can find the downloaded OTA file in my phone?
The OTA update file is stored in /cache
(need root to access), but it is not a .zip file like used by many other manufacturers — Sony uses a proprietary .pkg format for OTA updates, and currently there is no known way to unpack such files manually. Therefore the *.pkg file is useless for you, and the only way to update a phone with modified system files or unlocked bootloader is by using a PC.
Or, if you are already on 10.5.A.0.230, you may just ignore this update for now — it just adds the Google Music app, removes the Adobe Reader app (but it won't be removed if updating without wiping user data), and adds APN settings for more operators (which you probably don't need if mobile data already works for you).
Originally Posted by kurtfimmers
I don't want to update with pc companion as I think i might loose root?
Yes, you will lose root (and any other system modifications you had), but Easy Root Tool
should work with the 10.5.A.0.230 stock ROM even after the update.