Amendments or modifications to such certified plats, in conformity with lawfully adopted changes, or additions to the adopted master plan may be made and certified by the commission to the legislative body, and ordinances embodying amendments to or changes in such certified plats may be adopted by the legislative body, in accordance with the procedure prescribed by law for the enactment of municipal ordinances: Provided, That notice of the time and place when and where it shall be considered by final passage shall be sent by mail to the record owners of land located within or abutting on the lines of proposed streets, ways, places, parks, playgrounds, or other public grounds. Any such proposed amendment or change shall be submitted to and approved by the planning commission: Provided, That in case of disapproval the commission shall communicate its reasons to the legislative body which shall have the power to overrule such disapproval by a recorded vote of not less than 2/3 of its entire membership. Any plat of a street, park, playground, or public ground certified by the planning commission to the legislative body under this act shall be deemed approved by the commission without further submission thereof to said commission.