Use the Restore Family button in a family's Lead File record to move them from the Lead File back to your main system.
Families must be restored to your main system individually. There is no option to mass restore Lead Files back to the main system.
If the family to be restored had more than one student when they were archived from your main system, there will be multiple Lead File records for the family. Use the Restore Family button in any of the family's records to restore ALL students in the family back to one Family record in your main system.