You need XS++3.1 and flash drivers.You find all that here USB Flash Driver Installation - Guide - Top Sony Forums and here XS++ 3.1 Guide-Flashing, Customizing, Recovering - Top Sony Forums Read this 2 tutorials,gonnect phone with XS++ and post log here without IMEI number.
After that you can unlock that phone(if is CID52) for free,or with some payed service if is CID53(because for now there is no free support tools for CID53)