It looks like you know the potential solutions. Paying people less is a common option. You just increase their payments slower than the inflation so they don't

It looks like you know the potential solutions. Paying people less is a common option. You just increase their payments slower than the inflation so they don't burn the country down immediately. You can make people pay more, that's also a common option. A frequent feeling in France is that some people don't pay enough taxes. You can also redirect other taxes, the retirements pension scheme doesn't have to be a zero-sum actually. You can also print more money, because everyone does that all the time and it works well in practice. Modifying the retirement age is the lazy and capitalist way. Thankfully I'm not in charge, but I would do a bit of everything (including changing the retirement age of some category of workers).