I've given you three links above. Those are the step-by-step guides.
It won't help to multiple-posts a same question on a different topic within the same Forum. The answer is the same.
Your best chance of changing the Middle East firmware to a UK firmware is to follow the links above.
Read the instructions on those links, if don't understand then asked here with what/which part you don't understand.
Sent from my Galaxy S using Tapatalk
Followed your link to xda and found a post on flashing original firmware using Kies. Was a bit confused by the 'reg edit' bit but managed to work that out and updated the phone this afternoon to UK spec. Thanks for your help.
Now, whats this new Foryo thing LOL