How do you put R-134 in a 2000 mercury villager?

To add R-134a refrigerant to a 2000 Mercury Villager, first ensure the engine is off and locate the low-pressure service port, typically found on the larger diameter AC line. Remove the cap from the port, then connect an R-134a charging hose fitted with a gauge. Start the engine and turn the AC to the maximum setting; then, slowly add refrigerant while monitoring the pressure gauge to avoid overcharging. Once the desired pressure is achieved, disconnect the hose and replace the service port cap.