In my opinion this is no different from other goals (e.g. fitness). If you want have a fitness goal (running a marathon, powerlifting, etc.) you'd want to start small and easy, get your form right, and then progressively increase the resistance and intensity. Its better if you have a personal trainer, but it is completely achievable on you own if you understand your body, research and workout consistently. Similarly, We know our brain is incredibly resilient (neuroplasticity). So, if the goal is to remove the fear of stuttering, then we need to approach it just like working towards a fitness goal. Its better to work with a therapist, but at the end of the day we need to understand our own mind, and work gradually and consistently towards becoming more confident. In fact, I'd go as far as to say that this is the ONLY way to overcome our challenges with stuttering. Being afraid of rejection is a huge part in why most PWS do not speak as much as they should. So working on removing this fear is going to play a big part in their speaking goals.