You are already divorced. The first step in trying to put your marriage together is to start a dialogue. Call him up once or twice a week and chat with him. Will he converse with you? If that goes well for a month or so, then try getting together like a date, just don't call it that. Invite him for a cup of coffee or dessert or a meal. It's almost like you have to start your relationship over again.
If you know an elder or religious leader he respects, you might ask for a consultation with that person.
