Any city which shall have operated for more than six (6) years under the provisions of sections 50-801 through 50-812, Idaho Code, may resume operation under sections 50-601 through 50-708, Idaho Code, by proceedings held as sections 50-801 through 50-812, Idaho Code, provide for adoption of the council-manager plan. The proposition to be submitted shall be: "Shall the City of …. retain its organization under the ‘council-manager plan’?"