From the PHT, take a cab to Shinjuku station. I prefer the South entrance, the get-off is a bit ad hoc, but it works and the cab doesn't have to go well past the station to make a U-turn to the "New South" exit. There is now a lift down to the Narita express tracks from the South entrance so you don't have to carry bags down a flight of stairs.

The easiest entrance to get to by taxi is the West entrance, but it's a long hike from there to the Narita Express platform.

How gutsy are you and what class are you flying? There is an 8:03 departure that gets in at 9:29. Otherwise, you have to catch the 7:07am that arrives at 8:35. Reserve your ticket no later than when you arrive in Tokyo, with a one night layover it's preferable to waiting and having the hotel do it.