Using this brass reducing union kit is easy. First, make sure your refrigeration system is turned off. Then, connect the 3/4 end of the reducing union to the corresponding part of your system. Attach the 1/2 end to the other relevant part. Secure the connections with the included flare nuts. When using, always check for leaks. If you find any, tighten the nuts gently. As for maintenance, keep the kit clean and dry. Avoid using abrasive materials that could scratch the brass. If you notice any signs of wear or damage, it's a good idea to replace the parts to ensure the efficient operation of your refrigeration system.