I assume you are arriving into PVG and not SHA. I've always taken the taxi from the airport to the Westin; should cost approx. RMB 135-140 for the 40 minute ride. I doubt whether most drivers would be able to understand English, but just give the hotel a call while you are in the taxi, and pass your phone to the driver to communicate with the operator directly.

I've never tried booking a car, but I suppose there is a Westin hotel desk at the airport who can make such arrangements? I'm only guessing here.

The other option is to take the Maglev train. It involves a long walk from the arrivals hall to the station. From the airport into the "city", its about 8 minutes. Then, you have transfer either to a taxi, or to subway Longyang Station. From Longyang Station, go to Henan Central Station, and it's a short walk to the hotel. BUT, I THINK THE MAGLEV TRAIN DOESN'T OPERATE PAST 5PM, SO YOU NEED TO DOUBLECHECK BEFORE YOU MAKE THE WALK TO THE STATION.