Review the articles of incorporation. Depending on where your nonprofit is registered, some states allow incorporators to specify provisions in the articles on how and when an officer may be removed. For example, the articles might state that the president may only be removed "for cause."
Read the bylaws. Often, a nonprofit organization's bylaws specify how an officer may be removed. A certain number of votes by the directors may be required, or the bylaws may set term limits for all officers. The process may or may not be different when the officer in question is the president.
Review the board minutes to determine how the president was appointed to the position initially. Different steps may be necessary, depending on whether the individual was voted in by the board or appointed by another officer.
Meet with the board members and the president. Explain why you believe the president should be removed. The president may choose to resign voluntarily if he's aware that the board is considering removal. Unless the officer resigns or a specific procedure is set forth in the bylaws, it will be up to the board to remove the president.
Vote to remove the president. If the president was voted in by the board, it will be up to the board to vote the officer out. Unless otherwise specified in the bylaws, you will need at least a majority vote to remove the president.
Record the decision. The board secretary will be responsible for making a record of the decision, including how many members voted in favor of removal.
Vote to appoint a new president. In many states, nonprofit boards are legally required to have a president. The board must decide upon a new person to assume the position once the current president is removed.