unlocking bootloader
1 root your phone i used kingo root
2 unlock bootloader
3 go to the sony developping sitehttp://unlockbootloader.sonymobile.com/
4 fellow the steps untill they give the code to unlock your phone now download
http://xdaforums.com/showthread.php?t=2335555 for flashing software and connecting with abd
5 download
http://xdaforums.com/showthread.php?t=1560613 this put your imei code and your unlock code there and turn your device off and connect in fastboot (volume up and the connect cable it will say in the aplication if it worked warning be sure you make a backup becouse he is gonna make factory reset
6 dowload a custom rom (cm 11 with gapps) put it in a folder on your pc and extract the zip file put the normal zip file on your xperia go internal storage and not in a folder
7 download recover x from play store to install cwm or twrp
8 go in the flashtool from androxyde and
9 look if he gets root acces and that you have busybox installed (dont forget to put usb debugging on)
10 click the lightning and select fastboot mode
11click reboot into fastboot mode (via abd)
12 reboot into fastboot mode (via fastboot)
13 select kernel to flash and find the image in the folder you made on the pc instal it and disconnect your xperia when done
14 go in your recovery on your xperia by holding the power button and tapping volume up do this untill you see recovery
15 select backupp and restore and then backupp to save a copy of your rom
16Select "wipe data/factory reset" and "wipe cache partition" then "advanced > wipe Dalvik cache."
17 select instal zip from sd card choose zip from sd card choose the rom where you flashed the kernel of in the flashtool confirm and do the same with the gapss 4.4 if you dont do this you might have no playstore and google plus
18 select reboot and enjoy your rom
i am no develloper but i am pretty sure it will work it worked for me and if your divice is bricked no worry just go install the sony updater softwarehttp://www.sonymobile.com/nl/tools/update-service/ good luck there are enough how to videos on youtube.