Hi, I believe you're trying to open the file in Windows directly. Try opening it with Notepad, that should allow you to edit it. If you have something like a code editor or Notepad++ that would be even better.
Thanks for bringing this to my attention, I'll add a clarification to the instructions
Wow okay thank you - that probably would have been obvious to most others (I have very little experience using js) but I really appreciate the clarification!