How to re-map the uv map inside UE4

Hello,
I’m trying to re-map the uv map of a mesh inside UE4. Is there any tool or plugin to do that?

My object is an Invetor assembly converted to FBX with Showcase.
Showcase create automatic UVmaps that I can’t change.

My goal is to avoid passing though blender because I loose the origines of the parts inside the assembly.
Any hint or help would be most welcomed!