Используйте приложение APKPure
Историческую версию My Language можно получить на Android
Активируйте свой домашний язык на любом Android устройстве.
My Language is a simple handy application that let you choose and switch your system default language (locale) to your home language.
Root access will be asked only if needed (It should be required for Android 4.2+)
With an easy to use interface, just search or scroll down to your language, select it and it's done! the Locale changes are applied immediately with no need to reboot (but a few System UI apps may require a reboot to complete the changes in older builds).
The available language list is extracted from the latest Nexus builds, so some languages may NOT be supported on your device if you are running a different device or a different Android version.