How do you apply a new skin

I’m having trouble changing the skin applied to my WebHelp project in RoboHelp 2015. I have a project with a corporate skin applied. Now I need to use an entirely different skin (not a modified version of my existing skin). How do I apply the new skin to my project? I have the new skin in the Skin Gallery and I can select it from the Output Settings. When I generate the help I get the old look and feel. My current skin is NOT in the gallery and I cannot select it in the Output Settings but it is always applied to the project. So how do I change the skin used?

This cannot be that hard to do. The help says that after the skin is in the gallery I can select it and use it for the output. Not that I can tell.