[Koha] ‘Replace Record via Z39.50’

I'm migrating our library to Koha and sucessfully used marcedit to create marc records including item information. However, the marc records are pretty simple and I'd like to add more information. I saw Koha has the option ‘Replace Record via Z39.50’ from the Edit men u and I'd like to know if there's a way to do this for all items at once. I'd be happy about any suggestions -Katharina