It is possible to edit rules even if they are live in an email. For example, if you wish to change an image after the email has been sent, you can do this by updating the image in the rule builder. The changes will automatically pull through into the email. The Tag will remain the same so once a Tag has been added to the HTML, no further changes will be required.
Navigate to the rule you wish to edit and click on the edit icon. Progress through the steps, making the necessary changes.
Click on the pencil icon to edit the condition and the 'edit action' option to edit the action:
Click next to generate the Tag.
All changes will be automatically pulled through into the Tag. The Tag itself will not change - even if you have changed the images and/or the links. There is no need to make an amend to the HTML if you have already embedded the Tag.