How does the cartridge filter replacement procedure take place?

IT & LT Suction Filter Replacement:

1. Carry out pump down procedure.
2. Attach a suitably rated gauge manifold to valve 107A (for IT) or 107B (for LT) ¼” access valve mounted on suction filter housing.
3. Close valve 89A (for IT) or 89B (for LT) and front seat all compressor suction service valves.
4. Immediately vent the remaining refrigerant through a gauge manifold to a well ventilated area.
5. Remove housing end plate, replace gasket and filter.
6. Refit housing end plate and evacuate circuit down to 0.5 torr.
7. Close valve 107A (for IT) or 107B (for LT) and remove gauge manifold.
8. Open compressor service valves. Open valve 89A (for IT) or 89B (for LT).
9. Return plant to normal running conditions as in pump down procedure.