You've supported a book but want to increase your level of support. Here's how:
1.Log in to your Unbound account
2. Go to your supported projects page
3. Find the book that you want to upgrade and click manage project
Scroll down to the upgrade and donate box.
4. You'll be taken to a new page listing the available levels to upgrade to. Just click 'upgrade' on the level of your choice and then proceed with checkout.