You can only get the charges expunged if you get a deferred plea of guilty of no contest(or you go to trial and are acquitted) and successfully complete the deferral which would take five years in order to get the charges dismissed. After that you have to wait another year I believe before you can apply with the Attorney General to get the charges expunged. The details and the form are on the Attorney Generals website and it costs $45.00. You do not need an attorney to do this for you other than provide you with the information to fill out the form.
You need to concentrate on defense of the pending charges. Then your PD or private defense counsel can assist you to see what options are available under HI law.
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..