A president can overturn a predecessor's executive order merely by "issuing another executive order to that effect," the American Bar Association says.
Every president since Washington has used executive orders, which aren't explicitly referred to in the Constitution. As of the end of October, President Trump has signed 193 since taking office. Orders issued during October 2020 have included changes to civil-service job classifications, directives on water resources, the establishment of a "one trillion trees" council and mental-health care.