That’s a pretty drastic move — and the answer depends on your ages, and your entire financial position.
The easiest, and shortest, answer would be to move HALF to cash INSIDE your plan. That means your plan must offer a short-term money market alternative inside the plan.
If you’re already retired, then this is the time to do a direct rollover to a plan that offers safer alternatives. Read this: https://www.terrysavage.com/rollover-now/
But if you’re both still working, and you have at least a 20 year time horizon, you do need a long term conservative position in a diversified stock portfolio, easiest done in an S&P 500 stock index fund.