Really Basic Question How to use "Download Solutions"

This has got to be super simple but has me stuck. I found the link at the website to download solutions and I am able to navigate to the list of examples. When I link to Chapter 1 Get Started there are three files there… which one do I need and how do I use them?

I am working through the Random Password example had have an error I cannot find… wanted to look at your code (updated) to see what is going on but cannot get to your code.

let mainWindowController = mainWindowController(windowNibName:“MainWindowController”)

Thanks!

Clicking about at random, I got something useful to come up… not really sure what did it. It would be helpful to do a little description of how to use these solutions.

The code that showed up in the “solutions” really is different and does not show the error I got with the code in the book. Also none of this is mentioned in the Errata or the document on differences with Swift 2… I need to go post this on chapter 1 also.

Code in the book:
let mainWindowController = MainWindowController( windowNibName: “MainWindowController”)

Code in the solution:
let mainWindowController = MainWindowController()

This is going to be a long slog if differences like this show up show up every few lines of code.