(allows you to flash ANY ROM to the device regardless of the carrier. Just click RUU.EXE)
ONLY download ADB tools if you do not already have it!
1. Download adb tools here: download for WINDOWS or download for LINUX or from the attachments below
2. On your pc click on your local disk C: Drive (or D: drive for some) (WINDOWS users: Start > My computer > Local Disk (C)
3. Create a new folder called "adb" and extract the files from adb.zip into it. Make sure it doesn't create another folder in the adb folder when extracting
4. open command prompt (or terminal for linux) and type "cd" "followed by the path to your adb folder" (windows users can type "cd C:\adb")
5. Ensure your phone is switched on (regular home screen) and connect it by USB in charging mode (Ensure usb debugging is on settings)
6. enter the command "adb devices". This is to confirm your phone is connected. (It should come back with list of devices attached and your serial number)
7. enter the command "adb reboot-bootloader". (nothing further required device WILL reboot in bootloader)
IF it doesn't you can Manually put the phone in the bootloader/hboot mode
Navigate to fastboot by pressing volume down and pressing power button to select (power off > vol down + power on)
It will take you to the fastboot bootloader screen on your phone
Connect your phone via USB
Your Screen should now read fastboot USB
8. Enter the command "fastboot oem readcid". Make a note of your original CID.
9.enter the command "fastboot oem writecid 11111111"
10. enter the command "fastboot read cid" [it should confirm your CID is 11111111]
11. Press the volume down button twice on your phone and navigate to reboot bootloader, then hit power button to reboot the bootloader.
12. Bootloader will also say "CID-11111111" now to confirm You can now flash any ROM you like.
TO REVERT BACK TO ORIGINAL CID
i wrote on step 8 make a note of your original CID
follow all the steps above and then in place of step 9 enter the command "fastboot write cid YOURCID" where YOURCID is the CID you made a note of
so for me this would be "fastboot writecid O2___001"