70 ILCS 705/18
In any case where a fire protection district does not own or operate any fire fighting equipment and there are no bonds of such district outstanding and part of its territory shall be annexed to a city, village or incorporated town, which municipality was at the time of such annexation obligated by contract to furnish fire protection to the district, and where the board of trustees of such district consents, such annexed territory shall be disconnected from the district as follows: Certified copy of resolution giving such consent and containing a description of the boundaries of the area so annexed, together with a certified copy of the annexation ordinance or other proof of annexation, shall be filed with the court of the county where the fire protection district was organized. The court shall then enter a disconnection order stating that the territory shall be disconnected from the fire protection district. The circuit clerk shall transmit a certified copy of the order to the county clerk of each county in which any of the disconnected territory is situated and to the Office of the State Fire Marshal.
This Section shall not affect the right to proceed under any other Section of this Act for the disconnection of territory from a fire protection district.
70 ILCS 705/18