Managing a page from your Landing Pages list is very easy. Click the three dots next to the page you want to perform an action on.
You will be presented with the following menu from which you can pick:
The Comment and View Heatmap options will take you to the Preview version of the page where you can add comments, see comments and see the heatmap.
Duplicate option will create a copy of your page. You can Download a page in .instapage format and upload the file when creating a new page.
The Edit URL option will take you to publishing options where you'll be able to republish your page to your desired URL.