How to extract meshes from imported FBX files to use elsewhere

I have a situation where I am using two FBX base meshes for multiple male and female characters.

The bodies and associated skeletons of the characters stay the same, but I'd like to make the clothes they wear different- so I want the same animated characters to be able to be 'dressed' from a 'wardrobe' of clothing meshes.

I created a couple of characters in Mixamo that I am happy with as base male and female bodies. And have animations that I can apply separately to those that I am also happy with.

But now I am importing in other mixamo fbx files where the same character is wearing different stuff and I am having a problem.

When I import I get a prefab which includes the meshes I want to use but also the whole character that I have already sorted out- all I need from this import is their clothes. But when I try to drag the clothing meshes into another folder the entire imported prefab comes with it, when I only want that actual clothing mesh.

So how do I 'explode' the mesh I have imported so that nothing has any relation to anything any more?

 

just an addition, the meshes I am importing have a full body underneath the 'clothes' so they should in theory be able to be seperated

 

Looks like a job for UMA as far as I can tell... Looking into it