[Koha] Replacing all of the biblios

Good morning, I have done some major changes to my MARC records this summer. Is there an easy way to remove the existing records and replace them with the edited ones. The goal for this is to have records that have correct item types and remove records that were duplicate and had no items. The current database is about 500 MB and it should be about 70MB. Thanks for any information, Darla -- Darla Grediagin District Librarian Bering Strait School District Unalakleet, Alaska Web Address : http://bssdonline.org/course/view.php?id=51 Blog: http://aklibrarian1.edublogs.org/ OPAC: http://opac.bssd.org:8282