Dropping Last Name Off Minors Birth Certificate

My question involves name change laws in the State of: Arkansas

My son was given two middle names at birth. One of them is my maiden name. I'd like to remove his legal last name from his birth certificate and use my maiden name (his legal middle name) as his new last name. His bio father hasn't been in my son's life in a decade. My son is 11. The bio father is an abusive deadbeat with an arrest record and a list of 'former jobs' as long as my arm. My son also doesn't know of this man's existence. I know, I know, but I was told I couldn't have any more children. Plus, I didn't know at the time how this person was going to "turn out".

Any ideas how to go about this? How much it might cost? And of course the standard question, do I have to attempt to contact the bio father (if he can be located)?

Did bio-dad sign an acknowledgment of paternity or was he otherwise legally determined to be the father?

Yes?

You cannot change the child's name without his permission, regardless of whether you now think the fella you spawned with is a festering boil on the ass of humanity.