My son was hurt at school when he was a couple years ago and he still has a nasty scar on his head

Sorry your son was hurt. Not much to on in your question. Talk to a local personal injury lawyer to see if there's something that can be done. Most offer free consultations. Be well.

Be mindful of notice of claim requirements if public school, and statutes of limitation, and discuss it with a local lawyer.

You have probably waited too long to make a claim; due to the school being a public school they have a very limited time window to make a claim known to the city or county attorney.

School injury cases present a number of difficult issues - notice of claim requirement; sovereign immunity; causation; etc. If your son was a minor when the injury occurred, there is probably not a statute of limitations issue, but the others still may be problematic. Consult a qualified injury in your area as soon as possible. has a find a lawyer tool to help you.