If your insurance plan covers, you take them to a speech pathologist and they can give them tools as well as tools for parents to help a stuttering child. There is also all kinds of online material on techniques to manage stuttering. But most importantly be patient. Don’t try to force or finish their sentences for them. It will lead to insecurity of speaking. Let them know their stuttering doesn’t affect your love for them. If you can, try to understand the cause. Is it anxiety induced? Did your child go though a traumatic event? It’s a long process, not without it’s hard times, but it will get better for both of you. Best of luck. Feel free to contact again for more advice