How do you write a court mandated apology letter for punching your dad in the face?

Well you could start like this:

Dear dad,

I am dreadfully sorry about the incident that has occurred. It is to my understanding that taking my violence out on you is childish and morally wrong. If there is anything that I regret, it is purposely hurting you.

and so on...

Another try:

Dear Dad,

Having to write this apology is going to hurt me more than my punch did you...

(...On second thought, naaah)