This tutorial is obsolete. The code does not work anymore. This gadget was built with the Google Feeds API, which shut down in late 2015.
If you have the code installed on your blog, I'm sorry that it stopped working. Unfortunately, there's no way to make it work again. You can remove the code from your blog by deleting the HTML/JavaScript gadget with code that begins with this line:
<!-- BEGIN CODE IT PRETTY PINTEREST GALLERY -->
