How do you put freon in a 2004 Honda Civic dx?

To add Freon to a 2004 Honda Civic DX, first, locate the low-pressure service port on the AC system, which is typically found on the larger diameter aluminum line. Ensure the engine is off, then connect the refrigerant can to the port using a gauge and hose. Start the engine and turn on the AC to the maximum setting, then slowly release Freon into the system until it reaches the recommended pressure. Always wear safety gear and follow manufacturer guidelines, and consider consulting a professional if you're unsure.