[TUT] Change CSC code without losing data and enable Amr Hd voice

i found a way change csc code without losing data, but it need more test with different roms
we will work in efs folder please stop if you dont know what is efs and how efs backup restore. maybe you can lose imei. you agree to do this at your very own risk !

for enabling wb-amr hd voice, before you need look inside customer.xml in /system/csc/(your country code)/system/csc/
(full country csc code list in there http://forum.xda-developers.com/wiki/Csc)

<NbWbAmr>1</NbWbAmr>
<WbAmr>
<NetworkName>(your gsm provider)</NetworkName>
<WbAmrCodec>on</WbAmrCodec>
</WbAmr>
if you can see like that lines, can active hd voice for your country and your gsm provider.
if you cant see the lines and you are sure your gsm provider supports hd voice, you need modify file by manuel

let's start change csc code

before backup /efs folder.

change csc code in /efs/imei/mps_code.dat with currect csc code for your country.
delete /efs/nv_data.bin.md5 file and reboot phone.
nv_data.bin file will be re-build with your correct csc code.
that's all

sorry for my bad english. i'm learning it still :)