Since we have a number of language options there might be a slight confusion when you all of a sudden have to read everything in languages people on the other side of the world understand, or maybe your parents do? Who knows...
Anyway! Here's how to change it!
Go into the studio and click the "Settings" menu (which could be called different things like Einstellungen/Configuración/Paramètres/Inställningar).
Choose the "Language" option (which could be called Sprache/Idioma/Langue/Språk). Here's where you can find your desired language and click on it.