Publish the header
When you've completed all the steps above, then all you need to do next is publish your header.
To publish your header, navigate to 050 [Your Website] Website > Building Blocks > Website Content > Site Layout > Header
In that folder is a component named Header. Right-click on that component and select Publishing > Publish:
Select the site you wish to publish to and click Publish. This will send the header to the publishing queue.
Verify the header looks like you want it to, and edit/republish as needed.