Fathers Abuse from Childhood. How to forgive him?

My father is currently in a nursing home and is 63 yrs old and I am his son 29 years old. He suffered a stroke in 2016 and left him paralyzed and unable to walk. My dad physically and emotionally abused me as a child and got me arrested once because I defended myself from his beating and the cops chose his side.

It has been many years that I've spoken to him or seen him and I don't know if this is my mind trying to heal my abusive past, resentment, or just distancing because I don't want to talk to him. He did apologize to me and claimed he was a "terrible father". He did give some good memorable moments but about 75% of the memories were bad. I feel bad for not talking to him because he is alone and is likely suffering from dementia. He is not in a position to abuse anymore. How do I fix this relationship and forgive him?

Tl;DR: How to forgive my father for his abuse to fix our relationship?