Multiple instances of a prefab with different materials?

I have a relatively simple issue that I can’t seem to figure out:

I’ve purchased a model pack off of the Internet, and I’m using it as an enemy. The model pack provides many textures to apple to the materials of the model, to change his clothes. However, if I create multiple instances of the model, and try to change the clothes textures on any of the materials of any of the instances in the scene, it changes the texture on all of them.

How do I get around this?

A mesh renderer takes an array of materials. Make a material for each of the clothing options then tell the mesh renderers which material in the array to use.