Any public official may be removed from office. There are two ways to remove an official:
Recall election: Neglect of duty, malfeasance, or misconduct may constitute grounds for the recall of a public official. Voters may organize a petition, and if enough signatures are obtained (25% of the votes cast in the last election) within 14 days, then a special recall election is held asking voters whether or not to remove the official from office, and simultaneously electing a new candidate.
Impeachment: Accusations of misconduct of a public official may be heard in the House of Representatives. The House hears charges and considers evidence, creating articles of impeachment if a simple majority is reached. The Senate then tries the case, calling witnesses and considering evidence. The official is removed from office if two-thirds of the Senate votes for impeachment.
If the impeached official is from the Executive Branch appointee, the President simply appoints a new candidate, subject to approval by the Senate. If the impeached official is the President, Vice President, Speaker of the House, etc., then the next-in-line official moves up to take his or her place. In that event, a new official would have to be elected in order to fill the vacancy of the succession.
Once the official is removed from office, they may continue to use the site as a citizen, but may no longer seek public office.