macOS

My father is 75 and not very capable on a computer. He's got an old MacBook Air at home behind a typical ISP router for which he has no access controls (so no port forwarding).

My immediate need is actually not his machine at all, but the Raspberry Pi I installed at his house before I left the country and forgot to enable cron on so it's not doing what I need yet. However, it would be really nice if I could also do one of the following as well:

• VNC (or something) into his computer whenever something "isn't working" rather than doing the talk-him-through-it dance over Skype.
• Install a new OS (the Mac is no longer supported by MacOS). I don't know how plausible this is though.

My current plan is to email him a shell script that should create a reverse SSH tunnel to a server in Montréal or something and then I can shell into his Mac through there. It's not ideal though since we're still talking shell scripts and he's easily frustrated.

I know that in Windows land there are all sorts of tools scammers use to take over a machine remotely. Does Mac allow for the same thing? Note that I only have Linux machines available to me on this side of the Atlantic.