These two lines seem to be doing most of the work:
$url = isset($_GET['id']) ? $_GET['id'] : NULL;
$service = $model->getObjLangByUrl('service', 'service_lang', $url, LangId);
You can see that the first line extracts the parameter from the
$_GET array into
$url, then the next line retrieves the information. The other parts of the code just display various aspects of the
So your next step is to delve into your included files, search for the definition of that function on the second line I quoted above, and see where it gets the data from. When you look at that code and data, you may see a correlation between the content you are trying to modify and the way they are stored.
It looks very much as if this is some kind of content management system, though, so I am surprised that there isn't a way to edit the content without having to know about the code, as that's the whole point of a CMS.