1. Shut off power to the WPU.
2. Remove the bottom front panel.
3. Remove the valve core from the valve.
   
4. Place a wet cloth around the copper tube near the thermal expansion valve inlet and outlet joints. Use a torch to unsolder the connections and remove the expansion valve.
   
5. Replace the valve. Use a torch to solder the thermal expansion valve to the inlet and outlet.
6. Solder the bypass tube to the thermal expansion valve.