The receiver/drier should be replaced whenever the compressor is replaced. First, have the A/C system discharged. Next, disconnect the negative battery cable from the battery and the compressor clutch wiring harness. Remove the drivebelt, then disconnect the refrigerant lines from the top of the compressor, ensuring not to remove the refrigerant lines-to-compressor bolts unless the system has been discharged by a service technician; plug the open fittings to prevent dirt and moisture entry. Unbolt the compressor from the mounting brackets and lift it out of the vehicle. If a new compressor is being installed, follow the directions regarding the draining of excess oil prior to installation, and transfer the clutch from the original to the new compressor if necessary. Installation is the reverse of removal, replacing all O-rings with new ones specifically made for A/C system use and lubricating them with refrigerant oil. Finally, have the system evacuated, recharged, and leak tested by the shop that discharged it.