All who have purchased an eBook from us can download new updated versions for free. Just use the link in the email you got from Gumroad when you bought the book, or use the attachment-link supplied in our Gumroad eBook update emails.
You can also create a free account at Gumroad (our eBook distributor) by supplying the email account you used when you bought our books. This will give you access to the library of all your previously bought eBooks.
If you experience difficulties re-downloading an eBook, just let us know and we’ll send you the updates by email.