We don’t know much, but we know tax cuts and tariffs are on the agenda. I suppose that, while he might not execute the Fed Chair (that’s reserved for a select few), he is likely to try to otherwise eject him/her if policy is not to his liking.
On tariffs: A 10% tariff on all imports (oil too!) would result in a reduction in GDP even without retaliation (see Tax Foundation; Committee for a Responsible Federal Budget). A 1% reduction in GDP is extrapolated from the effects in the 2018 trade war.
On tax cuts: cut corporate tax rates to as low as 15%.
On the Fed: Fire the chair if monetary policy is not to his liking.