770 ILCS 45/6
Liens provided for in this Act may be foreclosed by an action in the circuit court of any county in the State of Illinois, or they may be foreclosed by advertisement and sale of the chattel, subject to the lien, in the following manner: That the person, or claimant, desiring to foreclose such lien by advertisement and sale, shall deliver to the sheriff of the county in which such chattel is then situated, a certified copy of the notice of lien duly certified to by the recorder of deeds where the same was filed, with the request endorsed thereon, signed by the claimant, or his or her attorney, for the foreclosure of the lien. Thereupon the sheriff, upon the claimant giving to him or her a bond as in cases of replevin, shall take the property described in the notice of lien into his or her possession, and for such purpose shall have power to enter any building, garage or other inclosure where the same may be stored or held, in the same manner as provided by law under an order for replevin, and shall at the time of such taking, deliver to the person having possession of such chattel, if such chattel is found in the possession of any person, and mail postage prepaid to the owner or reputed owner and to any mortgagee or his or her assignee if known, having a duly recorded or filed unpaid chattel mortgage or security interest upon the chattel described in such lien, a copy of the lien notice, certified to by the lien claimant or his or her attorney, together with an itemized bill of particulars of the lien claimant's demand, also certified to by such lien claimant or his attorneys; the person or persons claiming to own or to have an interest in the property, may at any time within 10 days after such service and mailing of notice herein provided for, deliver to the sheriff a written and verified denial of any allegation contained in the lien notice or bill of particulars, and if such denial or any allegation of payment on the part of any such person, or persons, be so made and served upon the officer then in possession of the chattel, such officer shall then and in such case retain the possession of the personal property, subject only to the order or orders of the Circuit Court having jurisdiction of the parties, or the subject matter, in a foreclosure action to be prosecuted by such lien claimant, which foreclosure action shall be filed and prosecuted within an additional period of 10 days from the time of service upon such officer of such denial or allegation of payment. In such case, if the lien claimant shall fail to commence and prosecute such foreclosure action within such period of 10 days, the sheriff shall release the personal property from such levy and deliver the same to the person or persons having, or claiming, an interest therein. If such action be commenced within that period of 10 days, the sheriff shall retain the property in his or her possession subject to the final judgment of the court in such action. If the person claiming to own the personal property, or to have an interest therein, or someone in his or her behalf, shall not, within the period of 10 days herein provided for, make a written denial of any allegation contained in the lien notice or bill of particulars, or allege full or partial payment of the sum demanded by lien claimant, the sheriff shall advertise the property for sale in the manner provided by law for the sale of personal property in the enforcement of a money judgment, for a period of not less than 10 days, and after giving such notice of sale, shall sell such chattel at public auction to the highest bidder for cash, to satisfy such lien, accrued interest, costs of seizure and filing and recording such lien and certified copies thereof, and storage; and the proceeds derived from such sale shall be applied to the payment of costs as herein provided, and the amount of such lien and accrued interest in the order named, and the overplus, if any there be, shall be paid to the owner of such chattel; provided, that any person claiming to own or to have an interest in the personal property, shall, after making such denial of any material allegation in the lien notice or bill of particulars, or alleging payment in whole or in part of the lien claimed, make, execute and cause to be delivered to the sheriff then having the possession of such chattel, a good and sufficient undertaking executed by one or more sufficient sureties in the sum of not less than $100.00, and equal to double the amount of the lien claimed, undertaking to redeliver such chattel in like order and condition as it was when seized, to the sheriff upon demand of such officer in the enforcement of a judgment, or in lieu thereof to pay to the lien claimant any judgment which such lien claimant, or his or her personal representative or assigns may recover against the defendant, or defendants, in any foreclosure action that may be brought to foreclose such lien within the period above mentioned, and further conditioned in the bond, any attorney of the court, shall thereby be authorized irrevocably to appear for the principal or surety, jointly or severally at any time thereafter, and enter the appearance of the principal or surety in any foreclosure action relating to the property then pending or thereafter to be commenced, without process, as a party defendant, then the sheriff shall deliver the personal property to the person, or persons, executing the undertaking. The sheriff shall pass upon the sufficiency of such undertaking and the sureties thereon; providing, that the circuit court having jurisdiction in any foreclosure action shall at the time of entering judgment of foreclosure, enter an alternative judgment directing the principal and surety to forthwith surrender the chattel to the sheriff to be dealt with in accordance with the terms of the judgment or in lieu thereof, to pay to the lien claimant the amount of the judgment; and provided further, that the judgment shall thereupon be entered against the principal and surety; provided, further, that any defendant may, in lieu of the bond of surety above provided for, deposit with the sheriff a sum of money equal to the amount of claimant's lien, together with an additional sum of $50, the moneys to be held in lieu of such bond and from which sums claimant's judgment may be paid.
770 ILCS 45/6