Dear Dad and Mom,
It's still there. The button did not disappear. It's always been there. I've assembled photographic proof of its enduring existence, seen below.
Before we begin, please put on your glasses.
You're correct when you say, “But I pressed it and it didn't bring up those choices you talked about.” That's because the button you've been pressing was assigned dual functionality, and pressing it normally only calls the primary function, a straightforward “enter” command – notice that “Enter” is written across its face.
Its secondary function is to switch between inputs – notice the word “input” written in parenthesis underneath.
If held down for a few seconds, the remote will call the input function. This will bring up the external inputs options menu, shown below.
To switch inputs, use the up/down buttons to navigate to the input of your choice (HDMI 1 is the satellite box, and HDMI 2 is the DVD player), and then press “Select” (the big round button between the up and down buttons). To select a different input, simply repeat the process and choose another option from the menu.
Note: There will never be a reason to choose the “TV” input, even though it will always be highlighted as a possible option. Its purpose is to receive airwave signals, which you can't receive because you don't have an antenna anymore; I took it down before you had the house reroofed. Don't fret. You don't need it. If an earthquake strikes you're better off with your satellite feed. Earthquakes don't knock out satellites, but they do sever cable lines and topple transmission towers.
The process is summarized below for quick reference.
Your loving son,