master of none's advise is great! I'd just add that I wouldn't go into very many specifics with the administration at first.. but I would bring up that your child is already reading, and what types of things/books he's reading. It's easier for them to swallow a kid reading early (not super uncommon) and that's typically the primary thing kids learn in Kinder. Starting with the fact that your child is already reading, and you'd like to know about early enrollment shouldn't be a huge stretch for them.
