How to change the language of Minecraft: Windows 10 Edition Beta?
Solution 1:
There is a button on main screen.
Solution 2:
I was asking this question in 2020 because there is no world icon main screen now.
It is located under the settings or whatever it is in your languages. In that picture it is ayarlar as in Turkish language. Click it and find languages.
Edit: Question turned into an answer.