My question involves name change laws in the State of: Indiana between 1967 - 75

I am trying to help a friend find his original birth certificate. He found out his mother was not married to the father on his birth certificate when he was born. She was married to someone else for several years when he was born. Most likely this person is his father. He would like to find out more about his biological father but cannot get any records without showing a family relationship. Therefore he would like to have his original birth certificate, or anoter court document that shows this man is his father.

What would the procedure have been in this time period for his current father to change the birth record? They changed: his mother's last name, his own first and last name, and removed his biological father's name.

Thoughts that come to mind are court records for an adoption, name change, of a change of paternity? could the records be sealed?

Thanks so much.