Guess you would just remotely disable any part that breaks. Once enough stuff has broken you just replace the whole thing.

Designing it would be a little bit like designing something that is going into space. You'd need to be very confident in your ability to remotely manage it over a long time frame.

I'd imagine they would want to build this cheap enough to just replace the entire thing when something goes wrong. Anything else seems very impractical.

It fails in place, then you replace the internals every five years as a single unit. After 20 years, you recycle the whole thing.