Please follow the below steps to change existing listing template with a new listing template.
⦁ Please click Settings -> Marketplace -> eBay ->Listing Template.
⦁ Following screen will be shown
⦁ Please click 'Assign this template to eBay Items' button.
⦁ Following screen will be shown.
⦁ You can search for products and assign the template for eBay active items. You can also update the changes to eBay by clicking 'Update eBay'