Believe me, this is a lot more detailed than it needs to be, I just wanted to be thorough. It's not really that complicated once you see what you're supposed to do.
DO NOT UNZIP THE FOLDER FROM GITHUB!!! IT NEEDS TO STAY ZIPPED!!!
The thing from zezula is called CascView. Open it, and click "Game Storage" then the game you want to extract models from. I have really only tried StarCraft, but in that one it seems that there is no real way to map out where the files are, you'll just have to guess and hope you get lucky. When you find a file that is what you think you want, click it, and hit "Extract." Use the settings you want, and save it to where you can find it. If you haven't already, go into Blender and go to "File: User Preferences" then "Add-Ons" on the top, then "Install From File" on the bottom of the new window. Go to the location of "m3_addon_master.zip" through the new window, and click "Install From File" once you've selected the folder. Then search m3 in the search bar on the top left of the screen. Only one result should come up, select the box next to it, and click "Save User Settings" on the bottom left. You should now be able to Import m3 files from "File" in Blender, which you can then export as .stl's.
Can anybody extract Warcraft 3 Models? I'm trying to get a Tree of Life and an Ancient of War for a thing called "Catan Pieces as Starcraft and Warcraft Figures" by RecklessRobbie. He doesn't seem to see the validity in my solution to his night elf problems.