Re-assigning material on an imported model

Ok, so I've got a model that I made in Blender and then imported into Unity. The model has around 5 different materials. I've got the materials all pretty much working (had to manually set the texture for each one) but one thing I haven't been able to figure out is how to change a material of an already imported model.

I.E. My model has a "skin" material that is just a simple diffuse, but I downloaded a much nicer looking material from the asset store and want to replace my model's "skin" material with the downloaded one. Is there a way to do that? I found a few answers where people were changing materials from within scripts, but I'd much rather just do it in the editor.