[Wally Dad]

Yep, that was the trick. It is very much like a car stereo. Once I pulled it out, I was able to drop a new HDMI cable in the back and hook it up. Of course, after putting it back, I realized that the default speaks that come on when powered up are in the Bedroom...aaaagh. It didn't look like it would be very easy to swap the speaker inputs on the back, so I've left it alone for now.