Change the Program source code

Hi All,

Here my requirement is need to change some 100's of programs, I need to comment the one authorization object which is there in the program, through some find technics and where used list technics I could able to find out in which programs the specified auothorization object exist.. but IS THERE ANY WAY TO REPLACE THE SOME PART OF THE SOURCE CODE WITH REQUIRED CODE..

Please help me..

Thanks in advance..