With the exception of the terms which pertain to the capital contribution of member towns, the transfer of property to the regional school district, the grades included, the size of the board of education and the representation of each town on the board and the towns to be served by the regional school district, the terms of the plan approved through referenda pursuant to § 10-45 may be amended as follows: If a regional board of education finds it advisable to amend the plan or if the legislative body of a town served by the regional board of education requests amendment of such plan, the regional board of education shall prepare a report on the proposed amendment, including the question to be presented, file a copy with the Commissioner of Education and the clerk of each member town and make copies of such report available to the public at a district meeting called to present the plan. After such public hearing, the board shall set the date for referenda which shall be held simultaneously in each member town between the hours of six a.m. and eight p.m. At least thirty days before the date of the referenda, the regional board of education shall notify the town clerk in each member town to call the referendum on the specified date to vote on the specified question. The warning of such referenda shall be published, the vote taken and the results thereof canvassed and declared in the same manner as is provided for the election of officers of a town. The town clerk of each town shall certify the vote of the town to the regional board of education and the Commissioner of Education. If the majority vote in each town of the district is in favor of the proposed amendment to the plan, such amendment shall take effect immediately.