He's made the point about a thousand times that he'll cut the federal payroll by attrition. By not replacing those who die, retire or who by some divine act, are fired.
And attrition can do it if helped along by a continuing pay freeze for the overpaid federal workforce and by substantial modifications to the federal retirement systems. As a minimum, the rate of employee withholding can be significantly increased to more reasonable levels (that’s been done before for existing government employees) and their retirement can be transitioned from being based on a high-3 years average salary to a high-5 basis. The dwindling number of non governmental employees with an actual pension system rarely have it based on a high-3 years average calculation.
A new 401K only retirement plan should be the only thing that all new federal employees are under just as is the case in private industry which creates the wealth that the government consumes. If it were up to me, the same thing would happen for current employees PROSPECTIVELY. That is, they would get whatever pension they earned up to now, but would not accrue further increases in it. They are not (at least I hope they are not) yet our overlords and our ruling class.