I pretty sure this one works like most models.
Import the model and drop the "warcraft3imported/" stuff so you just have the model name and its extensions. Import the skins and sopy the paths that have been given to you (eg. "warcraft3imprted/Zap1_Yellow.blp" becomes "Textures\Zap1_Yellow.blp")
Save your map, and check if you can change a model file to you imported model (use th imported dropdown menu). If this doesn't work, close World Editor and restart it. If this doesn't work, find out if the model is meant to have a different path. I have had a couple of models that I just couldn't work.
If this is still too confusing, PM me and I will put it into a map so you can copy it.
BTW, remember to credit your source, in this case abcdefghstuvwxy.