To edit newsletter preview:

1. Add the new newsletter to the /past-newsletters document management page: under Add/Edit, click "New..." then upload the new newsletter

2. Save it to the page by clicking "upload"

3. Get the URL for the latest newsletter: go out to the public (non-admin) view in another window and navigate to /past-newsletters, then right-click on the newsletter's link and select Copy Link URL

4. Go to /admin/newsletter and double-click the I-Frame icon

5. Paste the new newsletter's URL (preferably making it relative by removing the .com and everything to the left of it) and submit that change

6. Also while in /admin/newsletter, update the download link by click once inside the words "Click here" and then modify the link by clicking the Link icon in the toolbar

7. Paste the new newsletter's (relative) URL in the Link dialog and hit Submit

8. Click Update to save both of these changes to the Newsletter page