Hey there! I found a much quicker and easier fix to the locale problem.
Steps:
1. Firstly, replace the config.wtf in the WTF folder with your desired locale.
2. Then go to the properties of your "PandaWoW 5.4.8" folder (the main folder that contains the PandaWoW-32.exe and PandaWow-64.exe) and set the folder to read-only.
3. You're done!
This worked for me and I did not have to download any additional files. Let me know if it works. ;)