Just fire them and don’t replace them.
It would be far quicker.
As has been mentioned numerous times already, it is almost impossible to fire a government worker. If Congress were to cut funding for the positions, yes, you can lay them off. But as long as the funds are appropriated for the position, it is difficult to get rid of them. But the fact that funds are appropriated for the position doesn't mean you are forced to replace someone who quits or retires...