You can make changes to a live t-shirt in the "Manage" section of the Merch by Amazon portal. Select to "Edit" a live design and you will be taken through the workflow change the title, brand name, or description. You will not be able to change the t-shirt colors, t-shirt brand (American Apparel or Anvil) or the image.
If you need to change the image or t-shirt options, you have the ability to delete the current t-shirt from the site and create a new one with the updated options.
You can also simply delete t-shirts you no longer wish to sell under the "Manage" tab. Any t-shirts you delete will be subtracted from your total live t-shirt count in your tier once the deletion process completes. Please note, this can take several hours to process.
For more information, please see the update on our FAQ: https://merch.amazon.com/resource/201846470#productiondeletion