If the tutorial says to put it in your header.php file then you could just copy the header.php file in your Genesis Theme (The actual Framework itself), and paste it inside of the child theme that you are using. Then you can add in the code however the tutorial is suggesting you to do. Make sure you copy this file when making your edits and not the one inside the framework. Once you copy it to the child theme, it will be used instead of the one that is in the framework.
Also, the code that you pasted above didn’t show up right. Sometimes that can happen with bbpress depending on the code and how it is pasted. If it happens again, just use something like – http://pastebin.com/ to post your code. I’m waiting for an update, or a plugin that will fix this hopefully in the near future.