My question involves adoption law for the State of: Kansas

The biological father is in prison, child is 5 yrs old, he has only seen him a couple of times when he was just a baby. Mom is married and stepdad wants to adopt the child. They have been together since the child was 6 months old. He will possibly get out of prison the end of the year. He has a history of violence, drugs and prison all his life. His prison term was lengthened due to illegal actions in prison.

How hard would it be for the stepdad to adopt the child? This is the only father he has known.

Thanks