The following questions can be used to remove the vendors from existing item records using CSV import.
Steps:
- Create a CSV file containing the item’s internal id and vendor. The vendor column in the CSV file should be blank.
- Go to Setup > Import/Export > Import CSV records
- Select items in the Import type
- Choose the CSV file
- Click Next Button
- Enable “Overwrite Sublists” in advanced options

- Click Next Button
- Add the field mapping as below

- Save and run the import
- All vendors from item record will be removed