xian airport to north railway and terracotta army museum

There seems free bus offers to travelers who hold a G train ticket that day. You need to buy a entrance ticket for the sites first at the service center underground the north station and then get the boarding pass for the bus to and return. Or you can take a shuttle bus from the airport to Xian railway station directly. There are buses offered on its east square. After your visiting, you can take a taxi to North Railway or back to Xian railway by bus first and then go for north railway by subway.