Go to C:\Users\YourPCAccountUserName\Saved Games\WarcraftRemastered then open the PREFS.WAR file in notepad. There will be a few rectangles, letters and symbols but more importantly a language code at the end which should be enUS.
Also open your game folder/data/strings.
Now in the opened notepad replace the enUS with the language code which you can see in the file names of the .json files in strings folder that corresponds to the language that you want, then just save the changes and launch the game.
The languages supported are as follows:
Also open your game folder/data/strings.
Now in the opened notepad replace the enUS with the language code which you can see in the file names of the .json files in strings folder that corresponds to the language that you want, then just save the changes and launch the game.