Go to to the JR East (Japan Rail East) offices in either Terminal 1 or Terminal 2 of the airport. The train makes connections at both terminals.
Purchase tickets on the JR East "Narita Express" to Tokyo Station, where you can transfer to the bullet train (or "shinkansen" in Japanese.) The purchase of a ticket guarantees a seat, and the trains run from the airport to Tokyo Station every half hour during most of the day. As of 2010, the price for a ticket ranged between approximately 3,000 yen (for a standard seat) to 4,500 yen (for a first-class seat.)
Board the train in the direction of central Tokyo. If you're already at Terminal 1, the train will only go in one direction, as this is the last stop on the line.
Travel five stops from Terminal 1, or four stops if you board at Terminal 2, until you reach Tokyo Station. Exit the train into the station.
Transfer to the appropriate bullet train if you've already bought your ticket, or proceed to the ticketing office for timetables, reservations, and purchases. Follow the maps and signage within the station (or consult representatives at the information point) to guide you to your particular train or to the ticketing office. Tokyo Station is the city's primary train terminal, from which depart bullet trains on all major lines, including the Tokaido Shinkansen, the Akita Shinkansen, and the Joetsu Shinkansen.