1. The trial shall proceed initially as though the offense charged was the first offense; when the indictment or information is read all reference to prior offenses shall be omitted; during the trial of the case no reference shall be made nor evidence received of prior offenses except as permitted by the rules of evidence; the judge shall instruct the jury only on the offense charged; the jury shall be further instructed to determine only the guilt or innocence on the offense charged, and that punishment at this time shall not be determined by the jury; and

2. If the verdict be guilty of the offense charged, that portion of the indictment or information relating to prior offenses shall be read to the jury and evidence of prior offenses shall be received. The court shall then instruct the jury on the law relating to second and subsequent offenses, and the jury shall then retire to determine the fact of former conviction, and the punishment, as in other cases.