You're going to have to file an application with the New Jersey courts, at least 10 years after the last incident, for expungement.  You should have an attorney handle this, because notice has to be given to the prosecutor's office and there may be objections to meet;  you would probably not have enough time to hire an attorney and get a good response together, if you start this on your own and have objections filed.  The objections might come from the victim, as well, since the prosecutor's office will also follow up with them in this situation.