"The hotel can book you a driver (inexpensive) to take you to terracotta warriors. Plan on spending the day, as there are other interesting sites nearby."

Just as a matter of scale, we stayed at the Hyatt and booked a hotel car to see the warriors. I normally don't do this but we had only one day and wanted to see a much a possible. I believe the cost was about 800 RMB and included stops and tickets at 3-4 other 'attractions' on the way back from the warriors. We were allocated about 3 hours at the warriors and that is generally enough time unless you really want to go into minute details.