Inside ecore we provide two options to change the default-language: 

1) personal

2) club



1) To change the personal language (only for you), navigate to your profile at the top right or in the left navigation at the bottom and click on settings

At the Platform Settings you will find a drop-down manu to change the language. Last step is to hit the "update user"-button at the bottom of the page. 


2) To change the club language (for all users), navigate to Settings -> Platform

At the Platform Settings you will find a drop-down manu to change the language. Last step is to hit the "update satting"-button at the bottom of the page.