Socal Stories seem to be the best bet. And you have to be persistent and not back down. You have to make sure they do not feel any pain while trying to potty train them and you may have to do it very slowly. start by just having them sit on the potty with all their clothes on. And in other times have them practice taking off their pants and putting them on. Practice each little skill needed in a none thearting way. Then add the social story and add all the skills together. They are going to fight and scream and make it seem like you are killing them but just talk to the softly and gentally and walk them through each step with love and persistents.