I hope you're talking about hiring a lawyer. If it passes, that's the way this will be resolved.
It won't be resolved in court. The way the Illinois Second Amendment is written the law is legal. The amendment reads: Subject to the police power, the right to keep and bear arms shall not be infringed. That means they can do whatever they want until there is a U.S. Supreme Court ruling. What are the odds of that happening? Last time they didn't want to hear the case. Given time, Illinois is going to be an island of gun control surrounded by CCW states. I don't think anyone can imagine how bad crime will be then.