Sometimes you'll need to bulk edit barcodes to change a setting (occasionally our data is bad), if this happens to you, here's a quick how to.
Step 1: Go to Products, and once you have your criteria (such as Vendor, or Tag, or Product type, or a sort method), select the products you want to edit and click "Edit Products".
Example - if I want to update a bunch of barcodes, I'll select "More filters", and choose Graphic Novels.
Step 2: in the bulk editor, click "Add fields" and select "Barcode".
Step 3: Make changes to the barcode, and click SAVE - save takes a few seconds as it will update each product with your changes.