Login to Your Joomla Site
Go to example.com/administrator and login to your site.
Go to the Template Manager
Click on "Extensions" and then "Template Manager"
Open Your Default Template
rhuk_milkyway is my default template so I'll click on that name.
Open the Template Files
Click "Edit HTML" in the top-right corner.
Enter Your Code
Scroll all the way to the bottom of the page and post your code right above the final lines: . Then click "Save" in the top-right corner and you'll have finished.