7. Loosen the two captive screws and remove the filter case.
8. Remove and dispose of the old filter and insert the new one.
9. Put back the filter case and tighten the screws.
Replace the power-box 3 filter (2E7N3A)
The following steps explain how to replace the power-box fan filter 3 on 3FW25A model printers:
Replace the power-box 3 filter (2E7N3A) 221