Is that last paragraph actually a thing? Yikes! That sounds like the kind of advice one would give if they've only ever dealt with toy problems.
He says to turn the function into a class and local variables into private fields. So that you can split the function into small methods that operate on these private fields. I used it a few times in a company that had strict "no Sonar warnings" policy. But I hate the resulting code much more than the initial code.