To enable any custom skins (or custom controller overlay), all you need to do is click on the skin of your choice in the Custom Skins section and you will instantly see the new skin on the screen. There are 12 custom skins that you can use in the gamepad viewer. Still not working? Share the error in the comments and I will help you get it working for you. If you are facing any issues in connecting your controller to the gamepad viewer, try removing and plugging in the controller again.