RDFC3STII

I need to replace my water value. I got access to it by removing the white access panel above the gas pedal, but still having troubling removing the water valve. I need to replace the water valve which connects to the heater hose (driver side), but the valve has a screw(holding it) going towards the heater hose and the valve also goes straight up connecting to a flat thin metal. How do you disconnect the valve which is going straight up?