It’s not a difficult task if you are familiar with PHP and Smarty and are comfortable making local changes to your code.
Generally, URLs map to a page handler under /pages/ where the URL corresponds to the directory name. The index.php file in that directory loads an appropriate handler, and the handler manages the code to display the template.
Consider, for example, the journal index page:
/ojs/index.php/journal/index maps to /pages/index/index.php:
All operations are sent to the index handler:
The index() operation sets up and displays a template such as frontend/pages/indexJournal.tpl: