If your reader isn't listed or you're using Adobe PDF, the Nook file is likely to work. Open your downloads folder and click on the file to open it in your ereader.
To read it on your Kindle device, attach the file to an email, send it to your Kindle's email address (with any subject, and nothing in the body of the email), and it should appear on your Kindle shortly. You can also drag and drop the file onto your Kindle if you attach the device to your PC with a USB cable.
Choose your reader and download location: