This document provides instructions for transforming a 2D book cover design into a 3D book cover using Photoshop. The steps include downloading a 3D book mockup PSD file from psdcovers.com, opening the file in Photoshop along with the 2D design, and using selection and transform tools to place the 2D cover art onto the 3D book template to create a rendered 3D book cover. Additional details are provided on filling other book parts and adjusting layers and settings to customize the final 3D book cover image.