I assume you mean reduce everyone's benefits to zero and provide for some transition. Define the transition, and then pitch it to your favorite Congresspeople. I doubt you will get a single endorsement.
No, my post #75:
Here's my idea, the gov can keep all my employers contributions past and future, I invest my portion (7.65%) and the government doesn't owe me any benefits when I retire.
The gov returns all my contributions. That is the cost. They keep my employers future contributions to help fund current retiree benefits. Any shortfall would be another transition cost. The cost would be front loaded and would eventually disappear as retirees collecting benefits die. When all those receiving benefits are gone, all new retirees have their own self funded plan and the employers contributions would also fund the personal plan.
I agree, Congress would never do it. I'd be worried if they did because that would mean I had sunk to their ignorant level. The problem is explaining the benefits to the people who, after all, have an average IQ of 100. Lower average for democrats, of course.