The manner in which any municipality, within the class provided in Section 21-7-1 may change its form of government to the plan authorized herein, shall be as follows:

One or more petitions, similar in form and substance, addressed to the mayor praying that an election be held to determine whether or not such city shall abandon its existing form of government and become organized under a council form of government, signed by at least twenty per centum of the qualified electors of such city, shall be filed with the city clerk, who shall deal with the same as required with reference to other petitions.

If on the delivery of such petition to the mayor, it shall appear that such petition or petitions have not been signed by the required number of qualified electors of such city, the mayor shall at once certify such fact and immediately return such petition or petitions to the person or persons presenting the same, who may thereafter procure additional signers thereto and again file such petition or petitions with the city clerk, as above provided, as an original petition.

If it shall appear at any time from the certificate of the city clerk that said petition or petitions have been signed by the requisite number of qualified electors of said city, the mayor shall immediately refer the same to the board of aldermen. If it shall appear that said petition or petitions are in proper form and have been sufficiently signed by the qualified electors of such city, they shall, within thirty days, order, and provide, for the holding of a special election in such city, to be held, not less than thirty, nor more than sixty days, from the date of making such order, notice of which election shall be given, and the same shall be held and conducted as other elections in such city. At such special election the propositions to be voted for shall be: “FOR THE COUNCIL FORM OF GOVERNMENT” and “FOR THE PRESENT FORM OF GOVERNMENT,” which propositions shall be printed on the official ballot at such election. As soon as the return of such election shall have been certified by the persons holding the same, the board of aldermen shall at their next regular meeting, consider the same, and if a majority of the votes cast at such election, are in favor of the council form of government, then they shall enter an order providing for the election of a mayor, a vice-mayor and five other councilmen provided for under Section 21-7-7, at an election to be held on the second Tuesday in December next before the expiration of the terms of the municipal officers then holding office. Thereupon the said petition or petitions, and all proceedings had thereon, including an order of the mayor and board of aldermen that the form of government will be changed on the first Monday of January following the expiration of their term of office, shall be recorded in the ordinance book of such city, which record shall be evidence of all the matters and things therein contained. The mayor of such city shall immediately certify to the secretary of state that such city by special election has adopted the system of government provided for herein, which certificate shall be recorded in a book kept for that purpose by the secretary of state. In case it shall appear by said election returns that a majority of the votes cast at such election were in favor of the existing form of government, then the board of aldermen shall dismiss the petition, in which case no similar petition shall be filed for a period of one year from the date of such order, but nothing short of such election shall preclude the filing of the petition at any time.

Any city which shall have operated for more than two years under the council form of government may abandon such form of government and return to the code charter form of government by substantially the same procedure through petitions and elections as herein provided for change to the council form of government. Such change, however, shall take effect on the first Monday of January following the expiration of the term of office of the members of the council then holding office.