The link works fine for me, you need to click the first link on the google search page.
As for calibre, Im not sure. I have never used calibre as a front end to break drm. My tutorial is meant for the command line on a windows system with python 2.6+ installed.
I can tell you that python scripts should have a .py extension. Python doesn't know its a python file until it starts interpreting the file. As for starting the copy at line 24, dont do the entire file. The first line #!/usr/bin/python is critical, and you may want to change it to path of python26.
I hope that helps a bit. If not let me know. But since you are havinga problem with pdf, you likely want the pdf section of the tutorial.