The filter-drier/receiver-drier should be replaced whenever the compressor is replaced. To remove the compressor, first have the system discharged. Then, disconnect the negative battery cable from the ground stud on the left shock tower. Unplug the electrical connector from the compressor clutch. Remove the drive belt. Disconnect the refrigerant lines from the compressor and plug the open fittings to prevent entry of dirt and moisture. Unbolt the compressor from the mounting bracket and lift it out of the vehicle. If a new compressor is being installed, pour out the oil from the old compressor into a graduated container and add that amount of new refrigerant oil to the new compressor. Also, follow any directions included with the new compressor. The clutch may have to be transferred from the original to the new compressor. Installation is the reverse of removal. Replace all O-rings with new ones specifically made for use with R-134a refrigerant and lubricate them with R-134a-compatible refrigerant oil. Have the system evacuated, recharged, and leak tested by the shop that discharged it.