Is there a good way to convert multiple body parts or parasolids into assemblies?

I have a part with many multiple bodies. Is there a way to convert it into an assembly in a few steps? Or do I have to do the Save Bodies as Parts on each body, then re-assemble into an assembly?

I tried converting into a parasolid, then opening it with the 'Import multiple bodies as parts' option on. But it didn't seem to take.