How to force a model to use texture atlas uvs via editor scripts

I have written an editor script that takes a dae in the project, grabs all of its children, then generates a texture atlas of all of the textures that would be used for this model, after which I save the texture atlas out as a png that I can use in the project.

Is there a way to modify the model's mesh uvs via editor scripting to force the model to use the atlas texture instead of their default textures? Or would this have to be done at runtime?