1. Use a good file manager on Nokia N9 (e.g. FileBox) to navigate to /home/user/.local/share/applications
2. Find facebookqml.desktop file. Since you cannot share it to PC directly from here, use the FileBox to copy it to the phone's root directory, i.e. MyDocs (the directory you see in USB connection on PC).
3. Connect your phone to PC and copy the facebookqml.desktop from the phone to your PC. Edit it with system notepad. The contents of the file should look like this:
Edit the file and change it to:
Note: You can change the display name of the app in Name= line.
4. Save the changed facebookqml.desktop file. Send it back to your phone, and using FileBox copy it back to /home/user/.local/share/applications . Overwrite it if you want to substitute the old facebook app, or give it a different file name if you wish to keep both QML and HTML5 versions.
5. Restart your phone for the changes to take effect.