How do I remove all downloaded books from Bookshelf 9 (Mac/Windows)

Bookshelf for Mac and PC

Answer

Exit out of the Bookshelf application
With your mouse click on the Go menu (top of screen). At the same time, on the keyboard press and hold the Option key. A hidden option called Library will appear in the Go menu. (Note: If the Go menu does not show up, click on your desktop, then Go)
Click on the Library option
In the Finder window that appears locate Application Support > Books > VitalSource Bookshelf> VitalBook Library
Delete all the *.vbk files present
Launch Bookshelf
You will now be prompted to download your book again each time you click one.

Exit out of the Bookshelf application
Uninstall Bookshelf from the Add/Remove Programs option in the Control Panel
Restart your computer
Reinstall Bookshelf from www.vitalsource.com/downloads

In the Bookshelf application, click "My Books" to view a full list of titles.
In the top-right corner, click Refresh, then click the List icon (just below Refresh).
To the right of the applicable title, click "Book Details."
In the Details window, select "Remove from Device" (you may need to scroll to the end of the screen).
Click the "Remove" button to confirm.
Repeat these steps to remove any other applicable titles (if needed).
Click "Refresh" in the top-right corner again.
Click the book title in the list to re-download the eBook.

Removing books one at a time is not logistically desirable use the above instructions to remove all books at once from a device.