Expansion Valve Replacement

Remove the evaporator core (see EVAPORATOR CORE REPLACEMENT )
Remove the insulator (A) and bolts, then remove the expansion valve (B) and O-rings (C)

Fig 1: Expansion Valve, Insulator And Bolts With Torque Specification
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Install the expansion valve in the reverse order of removal, and note these items

Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage
Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption
Do not spill the refrigerant oil on the vehicle, it may damage the paint, if the refrigerant oil contacts the paint, wash it off immediately
Make sure that there are no air leaks
Charge the system (see SYSTEM CHARGING )