What do I have to order the professional plates online?
You must have a valid New York State vehicle registration in the passenger, commercial, or motorcycle registration class that does not expire within 60 days.The mailing address in your vehicle registration record must be your current mailing address.  Your vehicle registration record must match your current name if your name has changed.
and should I destroy the old plates?
Once you receive your new plates you will want to destroy your old plates to protect yourself against fraudulent use. Mark each license plate of the vehicle with a permanent marker.