Quote Quoting Wisconsin Statutes, Sec. 973.20(1r)
(1r) ... After the termination of probation, extended supervision, or parole, or if the defendant is not placed on probation, extended supervision, or parole, restitution ordered under this section is enforceable in the same manner as a judgment in a civil action by the victim named in the order to receive restitution or enforced under ch. 785.....
Whatever formality was followed by the court, the enforceability of unpaid restitution as a civil judgment is automatic under that provision.

If the victim chooses, the victim may file a satisfaction of judgment to discharge any remaining balance.