MPQ File Replacing

Ive been trying to replace files in the MPQ, skins and buttons work fine but my models dont show in game and return to default, though they show in the World Edit. Does anyone know why this happens? I dont understand where wc3 is getting the default models from.

Are you doing this for a map? Because if you are, you don't want to mess with the mpq, use the Import Manager.

No im replacing models from the MPQ, so they show up in Melee Games.

Umm... why?

.... because i want my game to look better

Ok, but you wont be able to play online...

Ive already done it and can play online, im just wondering were wc3 gets the original models from. Ive removed all the models of the originals.