Can I rename my 7 month old childs middle name?

His father is on the birth certificate but we are not married and he only sees our son once or twice a month. He also carries the last name. I live in Oklahoma. What would i have to do in order to change his middle name? His father demanded I put it as Cole (he was very controlling) but my family believes it is Daniel, after my father which is what I want it to be.