Hi

I found concrete5 a couple of days ago and now made my first site with concrete5. Usability for End-Users is great, but when it comes to the development I still have a question you maybe can answer:

If I want to theme a module - let's say I want to theme the navigation - where do I work on?

Concrete5 is not using a clean template engine like Smarty, so I cannot just make easy a new template file and just quickly theme it. How do I do it? Changing the header_menu.php in blocks/autonav/templates ?

But if I do so, what happens when I update the system? Doesn't it most likely change my files then? It is my understanding that an update should never interfere with customized files affecting the look, as logic and look should be apart. So it should be like far away from files that will be changed, for example in "themes/mytheme".

But I couldn't find any indication about how to do change the theme of a module in my theme-folder.