- Open the Project containing the In-Place family
- Edit the In-Place family
- Select all of the elements in the family
- Group all of these elements using the Create Group tool. Give the Group a name.
- Select the Group
- Do not Finish Editing the In-Place family yet!
- Go to the 'R' button (Application Menu) - Save As - Library - Group
- You will notice that the filetype is RFA!
- Save the Group somewhere.
- You Component Family IS the file that you just saved.
Here is a quick video:
Credit for this tip - KarelCAD support document