Translating to Spanish

[juampicerutti]

I'm a dual PhD student, and because of the agreement established between universities I have to do the thesis in both English and Spanish (I'm from Argentina). I haven't had any problems. However, when it comes to translating it, I managed to translate almost everything, but there are four things that I can't modify:
the chapters are automatically indicated as "Chapter", and I need them to be called " Capítulo".
Similarly, I need the header of the appendices to be "Apéndice", the Bibliografía to be "Bibliografía", and Contents to be "Índice".

Could you help me with this, please?

I add some screenshots of what I need to modify

Thank you,
Juan Pablo

[wannesm]

You can set Spanish as the main language instead of English. Change the lines in adsphd.cls that mention english where appropriate:

% originally: \usepackage[dutch,english]{babel}
\usepackage[spanish,dutch,english]{babel}

% originally: \selectlanguage{english}
\selectlanguage{spanish}