Replacing the mate reference to an instance in another assembly

I'm looking for a way to move individual parts from a subassembly to the main assembly without losing the associated mates. The part that I want to move is mated to another (layout) part in the subassembly. I've added the layout part to the main assembly and now I would need either beforehand or after moving the part to move the mate associations to refer to the one in the main assembly. Is there a way to do this?

Dissolving doesn't work because there are some assembly cuts and patterns in the subassembly that will get deleted when dissolving.