If you would like to modify the HTML of your header, here's how:
- Log in to your CoreCommerce admin
- Hover over the Design tab and click on Advanced Options
- Under Edit HTML/CSS, select header.html
- Make your changes and then Publish the file
- Be sure to make the same changes to secure.header.html as well
Most of the CSS that controls your header should be found in main.css. You can also modify any images that appear in your header by going to Design > Manage Store Images.