Leanpub has a 60-day "100% Happiness Guarantee", which means there's no risk in purchasing any Leanpub book, and we make it easy to get a refund if you've tried a book and want your money back within 60 days of your purchase!
To get a refund, you can login to your Leanpub account and go to your purchases page at https://leanpub.com/user_dashboard/purchases. Once you select the book, you see a 'Request Refund' link to the right.