Remove the heat shield (fixed by three secured screws) and pulling out the Vaporizer Heater itself from the “front” of the assembly (no screws), refer to Figure 3. When putting the replacement heater ...Remove the heat shield (fixed by three secured screws) and pulling out the Vaporizer Heater itself from the “front” of the assembly (no screws), refer to Figure 3. When putting the replacement heater in place take care of the right positioning of the Viton o-ring in the back, refer to Figure 5. Connected to the above is the possibility to mis-align the position of the heater shield / nozzle by obstruction of the aluminum ring – leading to the “nozzle type assembly” pushed into the heater shield.