Hey there, you might be want to know about extract models from games, or people called it ripping. Some people say it's a little illegal, but I believe that's okay. I have seen models ripped from Titanfall in L4D2 Steam Workshop. Anyway, back to ripping. Different games have different file format for their games. So there are many different way to extract it. You can easily Google it "extract (your game) models".
Once you find out how to do it, after you extract the model, you need to convert the model to another format because mostly those models only cannot be viewed in 3dsMax. I might recommend you Noesis, It can view and convert many 3d formats (afaik CS1.6, Half Life 1/2, most psp games), or you can Google it again. And importantly, you must have 3dsMax, which is not free. Pirate way!!!
But maybe some people already upload the models you want, so I suggest you to find it with Google "download (your game) model"
One of site I know that have ripped models is deviantArt. Google "xnalara deviantart" and you will find xnalara customized. Then go to gallery and you find a bunch of models. But you will need Xnalara and its requirement. Again, just google it
Hmm... Once you can open it in 3dsmax, you must doing thing by yourself. Like rigging, skinning, animating, and maybe make it more Warcraft friendly. Sooo... That's how you get and use models from games