With the Nokia 225 (manufacturer number 06438409099730, NK225 Dark Blue), you can usually change the language via the settings. Proceed as follows:

- Open the menu.
- Select Settings / Settings (often with a cogwheel symbol).
- Search for Phone or Language.
- Select Language.
- You should be able to select German from the list.

If German is not displayed, it could be that the device has a regional firmware that does not contain German. In this case, you would need to check whether another firmware version is available that supports German.