( Thanks to tutser )
1.For keypad lock text, copy the file "Aknnotpi.r01" from z:\resource and put it in E:\, edit and change the text with X-plore's hex editor, then copy it to c:\resource and reboot the phone.
You will see the letters" Kexpad unlocked" on the right side in the hex editor. In order to change these letters, you need to change the numbers in the middle of hex editor.I have changed them to "welcome tutser"
The file "Aknnotpi.r01" also contains the text for battery warnings : " fully charged" , "charging" and so on.
Please make sure that you do all the required changes BEFORE you put that file into c:\resouce as you can not modify or delete it once it is there.
This file also has the text "1 new message" , "1 new call", "? missed calls" and "? new messages" which you can modify.
2.For music player menu name, copy and modify the file "mpx.r01" and "mpxmainview.r01" from z:\resource\apps to c:\resource\apps.
FAQ:
1.What if you make a mistake ?
->You will have do a hard reset(*#7370#) to restore the text to factory settings.
2.How to add symbols to text using hex editor?
->I don't know all the symbols yet , but I am working on it.
% is 25
! is 21
' is 27
) is 29
. is 2e