Hey, everyone.
Chels here. N8 put me in charge of explaining how to put the header on your blog.
Here's how you do it:
1. Click on your new header (on N8's blog).
2. Save it onto your computer.
3. Get onto Blogger and click on layout.
4. Click on edit under your header (on the very top).
5. Upload the header there. Make sure you click the box saying "shrink to fit"!
'Hope this helps! Let me know if you need any other help!
Enjoy!