Q: How to Replace the Evaporator Core on Buick Century and Regal?
A: Disconnect the negative battery cable and discharge refrigerant. Detach all wiring from the evaporator/blower case, remove the accumulator, and seal refrigerant lines. Remove screws from the evaporator/blower case and take out the assembly. Separate assembly halves to access and replace the evaporator core. Reattach the accumulator, tighten the case, and reconnect seals and screens. Connect refrigerant lines and electrical harnesses. Reconnect the battery, then evacuate, charge, and leak test the A/C system.