Get there: More > Tools > Catalog > Batch item modification
This tool will allow you to modify a batch of item records in Koha.
From the tool you can choose to upload a file of barcodes or item ids, or you can scan items one by one into the box below the upload tool. Once you have your file uploaded or the barcodes listed you can click 'Continue.'
You will be presented with a summary of the items you want to modify. From here you can uncheck the items you don't want to modify before making changes in the form below. You can also hide columns you don't need to see to prevent having to scroll from left to right to see the entire item form.
Using the edit form you can choose which fields to make edits to. By checking the checkbox to the right of each field you can clear the values in that field for the records you are modifying.
Once you have made you changes you will be presented with the resulting items.