You can get a refund for any Leanpub book or course within 60 days of purchase. Here are the instructions:

http://help.leanpub.com/reader-help/how-do-i-get-a-refund

Please note that we do not have a way to "swap" books or courses.

So, for example, if you bought the English version of a book, but you actually want the Spanish version of the same book, you need to refund your original purchase, and then buy the book that you actually want.