A court issues an injunction to prevent a party from taking or repeating a particular action. Less commonly, courts issue injunctions to force a party to take a particular action. The injunction frequently takes the form of a court order enjoining a party from building in a certain place, from disturbing their neighbors, or from continuing a particular business practice. A court may issue a preliminary or temporary injunction while a lawsuit is in progress to prevent alleged harm from continuing. Following a full trial, a court may issue a permanent injunction. Litigants may beat an injunction by appealing it. The rules governing injunctions vary by jurisdiction, but the rules of each state usually closely resemble each other. Litigants may beat an injunction by appealing on many different grounds simultaneously.
Consult an attorney and file the appropriate paperwork to dispute the injunction in your state. Dispute a preliminary or temporary injunction in the trial court. Appeal a permanent injunction at the trial court only in states that permit a "motion for reconsideration," or otherwise, file your appeal with the relevant court of appeals in your state or federal appellate district.
Argue that the circumstances that that originally justified the injunction have changed, and that the court should modify or dismiss the injunction accordingly.
Explain that the law that authorized the injunction has changed, rendering it improper.
Show the judge that the injunction is unjust by comparing your situation with the situation of the party benefiting from the injunction.