How do you change the language?

I upgraded to Windows 10 Technical Preview from Windows 7 Home Premium, and I have not been able to change the language from English (Canada) to Danish. I was able to change it from English (United States) to English (Canada), but when trying to change to Danish it says that the language pack is not available and only enables the keyboard.

Jeg opgraderede til Windows 10 Technical Preview fra Windows 7 Home Premium og jeg har ikke været i stand til at ændre sproget fra engelsk til dansk. Jeg kunne at ændre det fra engelsk (canada) til engelsk (usa) efter, men når jeg prøver at ændre til dansk, det siger at sprogpakken er ikke tilgængelig og aktiverer tastaturet bare. Undskyld om min dansk er ikke godt, jeg kan ikke snakke meget af det.... jeg ønsker at have min computer i dansk for at lære.

Simple answer - you don't. The Windows 10 Technical Preview is available only in English, Chinese and Portuguese.

Yes, it's now only available in English, Chinese and Portuguese, but other languages will be added with future updates.

Unfortunately it is too early for your language for Windows 10 Technical Preview.

Expect localization team to complete your language in approximately six months is my wild guesstimate.