Paul,

They are changing headers and footers. Attaching a new template will do nothing. They need to copy the body of the template into a new template with the new headers/footers.

Any chance you could come up with code that will:
For each template in a folder...

1. Create a new template based on their new letterhead template
2. Copy the body of the old template (absent last section mark) into the newly created template
3. Save the new template with the same name as the old one in a second folder?

So long as their old ones have only one section, that should work. While I exect I could do this, it would be a week-long project for me and probably not as good as you could come up with in 10 minutes.