do you know what OTP means? OTP=one time programmed memory, so after program it is uniqe serial number/in phones IMEI/, how ever you can read it with UP&UP flash programer, but you cannot reprogram it........so there is only two ways to change this zone, the real is to change flash chip and program it like new one, also you must program OTP zone, another solution is named "patch" i belive if you use search button you will find evrithing here
WBR