Hi Jousma,
Thanks for posting a question to the MyWoodlot forum. MyWoodlot.com has step-by-step instructions about the application process. Check out those resources here:
https://www.mywoodlot.com/480a. Please note that as a minimum requirement for 480a, you must have at least 50 contiguous forest acres in New York State.
I recommend reading this blog too:
https://www.mywoodlot.com/item/would-480-a-work-for-you-and-your-woodlot.
Thanks and let us know if you have any questions.
Kind regards,
Kris Brown