Once you publish the changes, the favicon will display on your live Store Editor pages.
Configure checkout pages
Go to Checkout & Registration Manager.
Go to Page Configuration.
On all of your checkout pages, add the following code to the HTML HeadSection, replacing <store-id> with your store account name (store ID): <link rel="shortcut icon" href="/lib/<store-id>/favicon.ico" type="image/x-icon"/> Learn how to add code to your checkout pages.
Click the Save button.
Publish your Order Settings.
Once you publish your changes, the favicon will display on all of your checkout pages.
Tip: If you find that a Yahoo favicon is still in place of yours after the update, rename the favicon.ico file to something else such as favicon_new.ico then update the code in the HTML Head section of your site pages: