It is possible to edit rules even if they are live in an email.
For example, if there needs to be changes to an image after the email has been sent, the image can be updated in the rule builder.
All changes will be pulled automatically through into the email. Unless any additional parameters are added, the coding of the tag will remain the same, so no changes are needed to the HTML.
Navigate to the Rule Builder tag you wish to edit and click on the edit icon. Progress through the steps as normal, making the necessary changes:
Follow the steps as normal, clicking next to generate the tag.