first I'm not responsible for bricked phone
remember there may be full data reset on unlocking bootloader
if want to unlock follow bellow step
Its Better to take TA BACKUP[so that you can relock your bootloader and claim your warranty] http://forum.xda-developers.com/showthread.php?t=2292598
Download flashtool : http://www.flashtool.net/download.php
- First you should confirm that it is possible to unlock the boot loader of your device by checking the service menu. In your device, open the dialler and enter *#*#7378423#*#* to access the service menu.
- In your device, tap Service info > Configuration > Rooting Status. If Bootloader unlock allowed says Yes, then you can continue with the next step. If it says No, or if the status is missing, your device cannot be unlocked.
- go here http://developer.sonymobile.com/unlockbootloader/ and select your device and click continue
- now type your mail id..and tick agree the terms and condition on that page and click submit
- open your mail...see the mail from sony..it will have a link.. open it
- now open flashtool click BLU icon...and then connect your phone on flashmode by pressing and holding volume down button
and after sometime it will show another window to unplug phone/..
- unplug phone.., press and hold volume up button[Fastboot Mode] and connect the phone to pc again
- now it will ask the code...
- copy the IMEI from flashtool and paste IMEI on the link you opened from mail and tick two agree the terms and condition and click submit
- now again open mail....Check your mail,it will receive a mail from Sony with key...
- copy the key code in ur mail and paste in flashtool...Then click Unlock..
- thats it ur phone gets unlocked and if it restarts...pull the battery out and flash the stock rom again...
[NOTE1:while unlocking if u got errors..close flashtool and open it]
[NOTE2:After you unlock bootloader.U cant flash other device roms on your device..it will hard brick your phone..please use kernels,Roms made for your device]
@DevShaft for TA backup tool