Q: Updating from 5.1.1 to 6.1.2

Good morning... My first time on a community discussion board.  I followed the instructions  for the error above and when I open terminal and get to the step where I am supposed to put a # and a space before the gs.apple.com file, my termial does not display or show the gs.apple.com file.  The instructions said to navigate to it and had a picture.  I did not want to add the file as Im not experienced with terminal and not sure what that would do.

Any help is greatly appreciated.  Thank you very much.