Offline instructions: https://macmillan.force.com/macmillanlearning/s/article/LaunchPad-Download-an-e-book-to-read-offline
Offline access is available for the eBook only. Assignments and other activities require LaunchPad (online).
Summarized instructions to download the eBook offline:
Download the "Macmillan Learning eBook" app from Self Service.
Don't open the app or try to log into it directly.
From Schoology: open Launch Pad > eBook.
From the Help Menu > click "Download Ebook Offline".
From the resulting webpage (http://macmillan.vitalsource.com ) click the "Open App" button.
The previously downloaded app will open and sign in and show several eBooks, one of which will be the Macmillan title.
Click the eBook cover to start the offline download.