My sons last name is that of his mother. We would like to change it so that it reflects both of our last names hyphenated. We are not together but we share 50/50 custody and all is amicable. How do we go about doing this legally?

Will his mother consent to the name change? If so, there are a few forms that need to be filled out and notorized. Your court clerk should be able to help you find those.

Then its just a matter of some minor court fees.

If the mother is not in agreement... you may be out of luck. That being said, your son can call himself whatever he wants. If he is not trying to commit a fraud, he can go by any name that makes him happy.