Here it comes:

This is what Lian Jiet requested long ago.
Warcraft Version Switcher Guide
1. Extract the zip file from above link.
2. Check the extracted folder and open "Wvs.exe"











3. A warning message will come out, click ok.






















4. Set your Warcraft 3 Folder.








5. The application will be closed. Open "Wvs.exe" again.


























6. Click Switch Version Button (first button).
7. Double Click the Warcraft 3 version you want to switch.
8. The Warcraft 3 version will be switched.

Download Link:
Warcraft 1.24e Version Switcher