released family table with missing components also released as indepentent parts. How do I take those released parts and make them part of the family table. (I can't figure out how to do it without a naming error.)

I am updating/revising an existing (already been released) family table. It has most of the dash numbers, but a few were created and released as stand alone parts. (Basically, -2, -3, -4, -8, -9, -10 are part of the family table and -5, -6, -7 are independent.) How can I merge these existing parts into the family table? Everything I've tried produces a naming error in the workspace.