Legal Question in Family Law in Missouri

You can't. You are their father. The only way this could happen is if your wife remarries and her new husband wants to adopt like you did.

Perhaps you should try to be a father to the two children.

You can not "undo" the adoption. This should have been explained to you by your attorney at the adoption of these two children. Now, you will need to hire the very best dissolution of marriage attorney you can afford to protect your legal rights as much as possible under the circumstances.