Fauci has civil service protection. Only the head of of the Department of Health and Human services can fire him.
Even if he did fire him Fauci can appeal his firing as a civil servant if he was not fired for cause.
Simple enuff.
Trumpy tells HHS head to fire Fauci, and asks how long will it take? HHS head answers back: Give me a couple of weeks.
HHS then proceeds to make Fauci's life hell. Gives him an impossible task to complete such as proposing something ridiculous that goes against all of his scientific beliefs. Fauci is either unable to, or refuses to. HHS fires him for either incompetence and/or insubordination.
So Fauci appeals. Placed on temporary leave, with the HHS tying things up in the courts for months. While a Trumpy man (Jared? Actually I'd prefer Hopey- nicer to look at) takes over heading up the CDC in a temporary appointment.
The Jewel of the Mind is Colored with the Hue of what it Imagines