After you made your purchase, you should have been taken to a page with download links.
You also should have received a receipt email with download links, and a link to your Leanpub library, where you can download all of your Leanpub purchases any time.
You should be able to log in to your Leanpub library and download all your purchases here:
If you're new to Leanpub, here's how this works: we automatically create an account for you when you make your first purchase. This is done so that you can always access the latest version of your purchases. (Leanpub books and courses are often published in-progress by their authors, and can be updated at any time.)