This should be straight forward, but it was not. So, I believe this blog will help others who just couldn’t modify that plist file.
You can do a ‘chmod 777 Info.plist’ but still if you edit the file and try to save it, Mac OS doesn’t allow you to do it.
So, the work around is to open the file, edit whichever value you want to edit and save it in a different location. Then move the file (I used the command line) to overwrite the original file, and you should be done.