Very simple mod. All it requires is for you to extract the Sound folder into the World of Warcraft directory to replace the 6.0.2 stapler gun sounds with the vanilla gun sounds.
Example: Copy the Sound folder to C:/Program Files/World of Warcraft so it looks like:
'C:/Program Files/World of Warcraft/Sound/Spells/new files' and you're set, WoW'll just load the vanilla audio files rather than the 6.0.2 ones. Enjoy!