Adobe Photoshop (or equivalent if you know how to use it)
Autodesk 3ds Max
Download MPQ viewer, WMV, plugins
You will need Photoshop and 3ds Max
There is no step 3
Open MPQ Editor
Browse to your WoW directory
Go to Data\enUS and open patch-enUS-3.MPQ (your files/folder will be different if you are EU)
Inside of MPQ Editor, go to DBFilesClient
Extract AnimationData.dbc. Remember the location you extract it to
Close MPQ Editor
Open WMV, select a model. Choose something easy, like a monster (I used Malygos - he's under the second "Creatures")
File -> Export Textures
Click Export All
Click Export All to TGA
The model and textures are now in WMV/Export. Close WMV
Open 3ds Max
Click the hammer ("utilities") on the top right
Click "MAXScript" (second from the bottom)
Click "Run Script" and find the 3ds Max scripts that you downloaded
Open the file m2_import_v0.303.ms
Click "Run Script" again
Under the dropdown menu labeled "Utilities" (the default selection is "Convert to mr Area Lights", select WoW M2 Import/Export
Hit "browse" and select where you exported your animation data from the mpq in step 8
Make sure the three checkboxes on the left are all checked, and set m3 scale to .5 if it isn't already and hit save
Hit "browse" under Model Filename
Browse to where you exported your files from MWV in steps 10-14 (should be WMV/Export). Open the .m2 file
Hit "browse" under Skin Filename
Select a skin in that same directory. I'm not sure if it matters which one you select if there are multiples
A screen with meshes will pop up. You should probably leave this alone unless you are importing a character model (player model), just hit Import. It will likely take a little bit to load the model
Back under the Utilities dropdown menu, select M3 - Export
Leave the settings alone and hit Export
Export it to wherever you want. You should probably put this one in your project folder if you have one, to keep it organized. This will also take a little while
Close 3ds Max
Go to the folder you put the model in. Create a folder there called Assets, and in that folder make another called Textures. If you note, the file path name is the same one that was in the edit box when you exported the m3. If for some reason you want to have a different one, you must put your textures in the appropriate spot. For instance, if instead of Assets/Textures/ you decided to erase it and leave it blank, the textures would need to be in the same folder as the model.
Open photoshop and browse for files
Browse to the folder you exported the textures to (probably WMV/Export) and open all the .tga files
Ctrl Shift S to save as, don't change the name, hit save, and check 32 (for all the textures). For some reason the textures need to be resaved. Make sure you're overwriting the files, don't change the names.
Once you've resaved all the textures, close out of photoshop
Copy (or cut) all of the resaved textures (.tgas), and go to the folder with your exported .m3 in it. Remember those 2 folders you made (Assets/Textures/)? Put them in Textures. Make sure Textures is a folder inside of Assets, and the Assets folder is in the folder your .m3 is in.
Open the SC2 Editor
Right click and press import
Select the .m3 file and all of the textures and press ok. Don't be scared if your .m3 has a purple model. Make sure the file structure is intact (your model should be in one directory, with your .tgas in (your model directory)/Assets/Textures/
Check to make sure the textures were properly imported. They should be pictures in the little previewer - if they're pink/black triangles, you probably didn't resave the textures in photoshop correctly
Save. Make sure you save on the screen that has your imports, or your changes won't be saved.
Close your editor. Restart it after it's done shutting down.
Go to the data editor, select a unit. Select its main actor. Find Art-Model and double click it. Click View.
Find "Model". Double click. Browse. Find your model. It should be textured in the previewer. Click ok, ok. Close data editor. You should now be able to place the unit that you just edited, and it should have the correct model and associated textures.
Closing remarks - I'm a total newbie to this kind of stuff, I got really frustrated and I hope to spare my fellow newbies the same pain. It took me a really long time to figure out about the /Assets/Textures/, which is why I repeated it like 3 times. If you see any mistakes or skipped steps let me know.
The animations seem to be quite choppy, I'm sure if you know anything about 3ds Max you will know how to fix that. If you know , please post. Likewise, I don't yet know how to do character models+armor and stuff. Simple monster models are cool, but I think we'd all like a customized hero for our rpgs. If you find out how to do this, please post.