[Koha] Authorities in koha

Hi all I ask about how to upload authorities in koha, I need to know any way to upload authorities as Stage MARC records for import, I download authorities record from library of congress but can not upload it on koha. thnks MOHAMED MEGAHED Librarian & Technical support Misr International University Library Tel : +2 0100 - 22 – 97 - 962 Tel : +2 0100 - 49 – 49 - 096