kill a fly with an elephant gun

To take excessive, overcomplicated, or extravagant means or force to accomplish something relatively minor or simple. With this new system of issuing licenses, the government is trying to kill a fly with an elephant gun. Four separate departments now handle each stage of an application, when a single department could easily process applications from start to finish. Look, you've got some money issues, sure, but filing for bankruptcy would be killing a fly with an elephant gun.