If you want to add the language widget to the header, you will need to modify your header.html and secure.header.html files, and you will need to be familiar with HTML. To do this:
- In your admin, hover over the Design tab and click on Advanced Options
- Under Edit HTML/CSS, edit header.html
- Add ##LANGUAGES## into the code where you want it to appear
- Publish the file, then make the same changes to secure.header.html
- By default, the widget will display just like it does in the sidebar, with a header and as a drop-down. You will need to use CSS to modify the appearance.
If you want to use links or images, you can attach a specific URL to each image/link for each language. You will need to append /cart.php?l=4 to the end of your domain, e.g. http://mystore.com/cart.php?l=4. You will need to use the correct ID (which is 4 in this example), which you can see in the URL when you edit a language in the admin, under Site Content > Multiple Languages.