To edit a Preamble Template:
Click on the Preamble Template button in the Control Panel window.
Click on the drop down box to select the name of the preamble template you want to edit in the Add & Edit Preamble Code Set window.
You will be taken to a screen with two large text boxes.
In the top text box, edit the Preamble HTML code for the template.
In the bottom box, edit the Preamble ASP code.
Click the Save button.
You will be taken back to the Add & Edit Preamble Code Sets window.