Section 101. Discontinuance of streets

Whenever the common council shall
  contemplate the discontinuance of any street, it shall cause a notice to
  be published for ten days in the official newspaper or newspapers of the
  city of its intention so to do, and that all persons interested  may  be
  heard in reference thereto at a time stated in such notice.  If it shall
  be determined to discontinue the street and any person shall claim to be
  damaged  by  such discontinuance, such alleged damages, unless agreed to
  by the commissioner of  public  works  and  approved  by  the  board  of
  estimate  and  apportionment,  must be ascertained and determined in the
  manner provided by law for ascertaining damages for lands taken for  the
  opening of streets.  An ordinance discontinuing any street shall require
  the  affirmative  vote of three-fourths of all the members of the common
  council.  Whenever a street, or any part thereof, the fee of which is in
  the city, shall be discontinued, the lands embraced within the limits of
  such street, or any part thereof,  may  be  exchanged  for  other  lands
  within  the  limits  of  the city, upon such terms and conditions as the
  common council may by ordinance prescribe.