WPExplorer Pytheas theme help

Hello everybody,
i’m really happy with Pytheas thème.
I would like to change query order on portfolio’s. Instead of order by date I would prefer by name ASC.
I want to keep the defaut order (date) on articles.
I tried create a new query on taxonomy-portfolio_category.php but i didn’t achieve.
Where and how could I do that.
Many thanks for your help on this.