Default [Q][Miro]Unlock an unlockable bootloader

Hi guys, I have a xperia miro and the unlock bootloader allowed is "no". I saw some sites where they make it unlockable for around 20$, but I do not really want to pay for it, but when I saw that cm11 project going on, it just interested me more if someone knows how to do it pleasee tell me if i dont get some help, i guess i will have to pay it, so did anybody paid for that and what is their experience and did it really changed the bootloader status to unlockable "yes"

Sent from my ME173X using xda app-developers app
My Devices:

Asus MeMO Pad HD 7 White 32GB: Rooted/AOSP v2 ROM by superdragonpt/Stock Kernel

Sony Xperia Miro Black ST23i: Rooted/Stock/Tweaked ROM/Stock Kernel