You can't edit a label once you've purchased it on Pirate Ship
Labels Can't Be Edited After You Buy Them: There is no way to edit labels you've already created.
Once you've bought a label, it is valid postage, and any changes to the label might make the postage you paid for the wrong amount.
Request Refunds for Labels that Need Edits: If you've made a mistake and need to change the address, weight, dimensions, or anything else, the only option is to request a refund from USPS or UPS for that label and start over.