65 ILCS 5/4-10-1
Any municipality, which has operated for more than 2 years under the commission form of municipal government, may abandon its operation under this article and accept the provisions of the general law of the State then applicable to municipalities, by proceedings as follows:
When a petition signed by electors of the municipality equal in number to at least 25% of the number of votes cast for the candidates for mayor at the last preceding general quadrennial municipal election is filed with the municipal clerk, the clerk shall certify the proposition to the proper election authorities for submission to the electors of the municipality. The proposition shall be in substantially the following form:
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Shall the city (or village) YES of.... retain the commission --------------------------
form of municipal government? NO
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In municipalities which have adopted the City Election Law, however, this proposition shall be filed with the clerk of that board. However, in municipalities with less than 50,000 inhabitants this proposition shall only be submitted within the year preceding the expiration of the terms of office of the elective officers of the municipality and shall not be submitted more often than once in that year. In municipalities with 50,000 or more inhabitants this proposition shall not be submitted more often than once in 22 months.
If a majority of the votes cast on this proposition are against the proposition, the officers elected at the next succeeding general municipal election shall be those then prescribed in Article 3. Upon the qualification of these officers the municipality shall become a city or village under this Code, but this change shall not affect in any manner or degree the property rights or liabilities of any nature of the municipality, but shall merely extend to the change in its form of government.
The first city council or board of trustees elected after the abandonment of the commission form of municipal government shall have the same number of alderpersons or trustees as were provided in the municipality at the time of its adoption of this article, and the municipality shall have the same ward and precinct boundaries.
65 ILCS 5/4-10-1