If you created a guide and forgot to add a particular page OR if your workflow changes and you need to add the new page into your guide you can do that easily with Nickelled.
Login to https://dashboard.nickelled.com
Find your guide and click on edit
Then you can either 'Import a page' from the options menu. This allows you to import multiple pages and steps from existing saved guides.
Or use the "BROWSER" tab to navigate to the site with the missing page
If you need any help, just let us know.