Direct bus from Chongqing to Xiannü Town Tourist Center ?

I learned that going to Wulong Karst is to take a bus from Sigongli station to Wulong station and then take a van/bus to Xiannü Town Tourist Center. From this website I learned that I can take a tour bus from Longtousi Tour Bus Center to Xiannü Town Tourist Center, which is a lot more convenient and faster. Please advise how to go to Longtousi Tour Bus Center.