WHAT CAN YOU DO IF THE WRONG NAME APPEARS ON A POLICE REPORT???/?

My brother name is on a police report and they have a wildcat warrant for him the address , birthday is incorrect and the name is his. It is his ex girlfriend but she claims she told them a different name. He hasnt been arrested yet, can my brother and his ex go before a judge and explain that it is wrong the name is his cousins and they have the same last name yes she is a hoe..lol.. but seriously do he has to arrested before this can be fixed it is an ualt charge and she claims that she told the police a different name but she signed the paper ( victim notification form) can they just walk in the court together and see a judge on the day he see prisioners and tell him the problem. what will happen and what can they do??/ Please help if u know