Step 1 : Introduction to the question "What amendment can be invoked to remove a President from office?"
...The 25th Amendment clarifies the line of presidential succession, which hadn't been codified up to that point. Ratified in February 1967, it also allows for the Vice President and a majority of Cabinet members to decide if a President is "unable to discharge the powers and duties of his office," and remove them from the position, though this clause has yet to be used.