ยง  421. Proceedings thereon. If an objection to the sufficiency of the
  impeachment be not sustained by a majority of the members of  the  court
  who heard the argument, the defendant must forthwith answer the articles
  of  impeachment.  If he plead guilty, or refuse to plead, the court must
  render judgment of conviction  against  him.  If  he  deny  the  matters
  charged  the  court must, at such time as it may appoint, proceed to try
  the impeachment, and may adjourn the  trial  from  time  to  time  until
  concluded.
Structure New York Laws
Article 13-A - Judicial Proceedings for the Removal of Public Officers by Impeachment
415 - Impeachment to Be Delivered to President of the Senate.
416 - Copy of Impeachment Served on Defendant.
418 - Proceedings, if Defendant Does Not Appear.
419 - Defendant May Object to Sufficiency Of, or Deny Impeachment.
420 - Form of Objection or Denial.
422 - Two-Thirds Necessary to Conviction.
423 - Judgment on Conviction, How Pronounced.
426 - Officer, When Impeached, Disqualified to Act Until Acquitted.
427 - Presiding Officer, When President of the Senate Is Impeached.