If you need to customize the Smart Template header, here is how:

1. Log in to the administration page.
2. Click Content then Edit Templates



3. Click the smart_template/ link



4. Click custom/link
5. Click header.tpl link



The following screen will allow you to edit the header .tpl file. Before making any changes, please make sure to copy out any text you plan to edit or remove.




Here is the actual path:
skin/smart_template/custom/header.tpl