I tried this today and filled in some of the blanks with step one.
You will need Sketch Up 2013 or older for this plug in to work. In the 2014 version they updated the coding language meaning this file type isn't supported any longer and hasn't been updated by anyone. I found a download of 2013 (Free Version, calm down)
http://www.mediafire.com/download/hxwt3 ... hUpWEN.exe
This is the plugin used for the conversions. The actual link is on a forum you have to sign up for so I went on ahead and took the bullet for you guys.
http://www.mediafire.com/download/iewdo ... ghtMap.zip
To install this plugin you must first have SketchUp installed. If you have the program open you will need to restart it before the plugin shows up in the menu. The folder is located in the installed directory (default C:\Program Files\SketchUp\SketchUp 2013\) and you will need to drag and drop the .rb file into the plugins folder. It is now installed and because an item is populating the plugin folder it will now appear in the menu bar.
Believe that covers everything, good work on the tutorial.