Tools :
Flash tool[latest version] google it, or check on my previous post
Pc Companion [Optional]
Gordon Gate from latest flashtool
S1 Tool search on XDA-developers.com
X8 on debugging mode

How TO :

Install PC COMPANION
Install Gordon Gate
Install Flashtool 0.6.5.0
Setelah sudah semuanya Matikan HH anda lalu launch flashtool
[ Turn off X8 and launch flashtool]
click menu Plugin pada flashtool trus pilih device anda E15 X8 lalu OK
[Click Plugin menu on flashtool and choose your device [E15] click OK
Tahan Tombol Back lalu masukan USB ke PC
[Keep pressing back button on X8 and Connect USB cable to PC]
dengan Otomastis Unlock Bootloader akan berjalan ......
[Dont worry, let the flashtool do its work :D]
Setelah selesai boleh di cek dengan s1 tool
[after all those things finished, you can check with s1tool]
Congrats your X8 has been unlocked



credits to Sony Ericsson Xperia x8 indonesia group