Applying Clothing Via UMA Using Editor Window Slot Builder

so I recently just finished youtube tutorials 101 and 201 series for the UMA tool for unity3D.
there is a huge issue though. getting downloaded fbx or obj clothing to be read in the Slot Builder Skinned Mesh Render.
I tried adding the clothing i downloaded into an empty gameobject added a skinned mesh render then made it a prefab. however, that still did not work.

i also tried downloading the FBX and OBJ into blender and instead of exporting out I saved the file into unity3d. however, I still can't get the slot mesh to read my object or fbx in-order to make an outfit. And I think the Asset is not loading cause it does not show on my UMA when I press play.
This is what I downloaded: https://www.turbosquid.com/FullPreview/Index.cfm/ID/1338957

How and what steps in what order do i need to do in-order to get this object to show on my UMA for clothing? I re-watched UMA 201 part 5 like 5 times now and followed along. and there must be something I am not doing correctly. I just can't seem to recognize my mistake. any help will be greatly appreciated.