§ 970-m. Amendment of redevelopment plan. If at any time after the adoption of a redevelopment plan for a project area by the legislative body, it becomes necessary or desirable to amend or modify such plan, the legislative body may by resolution amend such plan. Such amendments may include a change in the boundaries of the project area to add land to or, prior to the issuance of indebtedness pursuant to section nine hundred seventy-o as provided by such redevelopment plan, exclude land from the project area. An amendment or modification of the plan shall be approved pursuant to subdivisions (a) through (g) of section nine hundred seventy-h of this article. Upon adoption of the amended plan by the legislative body the legislative body shall transmit the amended plan as provided by subdivision (h) of such section.