Stuttering can't be *cured*. There's many different breathing exercises and vocal tricks that can be very effective at minimizing a stammer to the point where it's barely noticable. But this requires intense practice on the stutterers part. It can often require that you have to alter the entire way you speak and breathe. It's certainly not something that can be mastered in 3 days. You'd be best off consulting an actual (good) speech therapist.