Can a President, or Congress ...

... remove an FDA commissioner? What is the process, if any, to short-circuit their term?

We do not want at will firing, I suppose, but if the independent agencies have been infected, then they have already been politicized. The top leadership needs to go. How to do that without turning these agencies into presidential fiefs with more lickspittles running the show the next time a thug occupies the WH.