How can I create a Material-Scaling Function?

I’m in the early stages of developing a game using UE4, but I want to use the starter content materials to get something half decent up-and-running. The only problem is that the UV coordinates of all of the models I’ve created are scaled wrong when it comes to the materials within the starter content pack. Instead of going into Blender and altering the UVs from there (which were generated using “Smart UV Project” for simplicity), I believe I could make some sort of material function that takes in a material and scale, then outputs the resulting material. The problem is, I’m not really sure how to do this. So far I’ve got 2 function inputs; a scalar parameter (for the scale), and a material attributes (for the input material).