how do i make a unit's model a spell, or a doodad model? like if i want to make a unit that looks like the starfall on the spellcaster. and i have the Abilities\Spells\NightElf\Starfall\StarfallCaster.mdl. and a whole list of all the abilitys.
You need one of the enhanced editors to do that. With those, though, it's pretty easy. Just find the mdx or mdl you're looking for, and copy it into the unit's model field (in the enhanced editors, this is a type-in field, not a drop-down menu)