However, this needs to be phased out. Nothing in the Constitution empowers the government to be in the insurance business and they fail miserably when they try anyway. If we want to have retirement insurance, let the private sector market it.
In the meantime, we'll need to find ways to fund the current unfunded SS liability. I'd start by cutting all unconstitutional and superfluous government programs (in other words, most of them).
Next, I've seen suggestions that we sell off government assets to raise cash. This might be a good idea, I don't know. Possibly worth looking into. Don't flood the market, but sell off as we can.
Also, perhaps sell long-term government bonds and use the proceeds to fund the current "entitlement?" Yes, this creates public debt (actually just shifts the debt because we already have the liability), but it's better than the current ponzi scheme. At least it's not forced. And, it can be controlled and phased out over thirty years or so via the long-term selling off of existing government assets (if that is feasible) and or the phased shifting to private insurance companies.
Encourage people to use part of their tax savings to buy the bonds or purchase the insurance or otherwise invest their money. You cannot force people to save for retirement, but you can encourage it, and you can make it attractive. But more than that, you have to educate the people and allow them the freedom to fend for themselves.