I've read all about macros and inputs and I'm still confused. My Amazon Fire TV device is on a different HDMI port than my Xfinity cable service. When I'm on one and want the other, I want to click it and have the input change and the source appear (that is, if I'm on Xfinity and click Fire TV, I want the Fire TV to appear on the screen because the HDMI input has changed). Is there a simple-to-follow, step-by-step guide on how to do this? Thanks...