This tutorial goes over how to enable the spatial analyst extension in ArcGIS™. The video corresponds to Chapter 1 of the G2G User Guide.
The User Guide and tool downloads can be found here: https://gray2green.jimdo.com/.
The G2G Tool is a product of the University of South Florida in partnership with the University of Florida and Thomas L. Singleton Consulting with grant funding assistance from the U.S. Forest Service.