From the Bookshelf part of Chatbooks.com, click into the subscription you want to adjust.
Click into the settings wheel located in the upper right-hand corner.
Click "Manage subscription."
Click "Number of books."
Scroll and click if you'd like 4, 6 or 12 books per year.
Click "Save."
Your subscription settings have now been updated.
Learn how to do this on the Chatbooks app here.