There is a Light Rail / Bus Station across the street from the Chase Tower. Use the following links to get more information. You will want to get to the Central Station at Central/1st Ave and Van Buren. It appears to be number 12.
General Light Rail Information
http://www.valleymetro.org/metro_light_rail/
Routes and Schedule Times
http://www.valleymetro.org/bus_schedules/bus_routes/BusSchedules.html