Applying texture on commercial model

I have purchased a foot model form TurboSquid along with a number of texture files. But I am at a complete loss how to apply the textures. The foot is the $89 one.
When I do a Smart Unwrap and apply the foot texture, it wraps to the wrong co-ordinates, stretching the skin in weird directions.

I’d assume the model would already be uv unwrapped so if you unwrap it yourself all the textures will become useless. Just apply the textures to the foot setting the mapping to UV
If you import the obj it should automatically bring in any textures and add them to the material.

Thanks Richard.