My ex-husband has an extensive criminal history I have full custody and a current PFA, he hasn't seen her in 6 months and his last name will only cause her grief, he has 5 grown children who he has never taken care of and his last name carries baggage that will have people judging her. He is pending a jail sentence at this point.

You will have to either get his consent, or due to his legal background you may be able to get a judge to grant you permission. Depending on your state laws, if there is no contact you have to print an add in the paper requesting the change if he does not respond to any form of contact with you trying to change her name then the judge should grant it with no problems. Read up on state laws and that should point you in the right direction.