Bulk Discounts is a very simple app and most of the usual functions for editing discount codes can be found in Shopify's Discount screen in their admin. We decided there is no reason to change this. You can view, edit, and delete codes, individually or in bulk, in Shopify's Admin.
1. Click Discounts on the left of the Shopify Admin
2. Select your discount set - It will have an App tag on it
3. Click View all codes
In there, you can alter the codes in any way Shopify allows