Using this ARCO marine relay is easy. First, make sure your Mercury or Mariner outboard is turned off. Locate the old relay and carefully remove it. Then, install the new ARCO relay in its place, making sure it's properly connected. When it comes to maintenance, keep the relay clean and dry. Check the connections regularly to ensure they're tight. If you notice any signs of damage or malfunction, don't try to fix it yourself. Contact the manufacturer right away. Remember, this product can't be returned to the place you bought it from, so always reach out to the manufacturer for any problems.