If you can, get a photo of his remote and save it. (bonus if it's his actual remote with the worn down buttons or whatnot)
Draw a circle around the button (arrow pointing to it optional) and text the pic back of which button to push. Repeat as needed.
If you can get him to text you a photo of the TV screen - circle and repeat.
I have an older friend with a TV/remote that is close to ours, but slightly different. Having these reference photos helps with the "language barrier" and the minor differences in layout.
Since I started making it visual and texting photos, it makes it much easier. Because even I, with my CS degree, can stare at a screen (or grocery shelf), frustrated, and not see the very obvious blinking whatsit that I'm looking for.
We used to say, " if it was a snake it would have bit me" but snakes are also well known for blending in , so it makes sense that we don't see things until we see them, especially when we are stressed.
This is always my response. Hacking a lot of times comes down soft skills, where bad people get you to give them your sensitive information. (Your pornstar name is the street you grew up on and your first pet's name, finding your mom's maiden name on facebook)
If someone is in an office, having a post it or notebook is a bad idea, especially if your area can be accessed by the general public (like front desk people, or anyone who takes walk-ins)
But for a person living alone, or with people they trust, having a hard copy in a safe place is really safe. The Online Scammer isn't going to break & enter into everyone's homes to get their post it passwords.
(And it gives them the ability to give a trusted person access if they end up in the hospital or something, without having to share that info 'just in case'.)
The threat is always greatest (if you don't fall for phishing easily) from the people inside your house. The ones that could steal your jewelry, cash, pick up your mail and open accounts, or just outright sit in your chair and access your computer.
In that case, even if you have a password manager, chances are good someone with physical access to you can find or figure out that one password. And like Bytemeister says, you have way bigger problems in that case.