Using this dog harness is a breeze. First, hold the harness open and gently guide your dog's head through the larger opening. Then, bring the straps around your dog's chest and fasten the side - release buckle. Make sure it's snug but not too tight - you should be able to fit two fingers between the harness and your dog's body. When it comes to cleaning, you can use a mild soap and a damp cloth to wipe down the harness. Avoid using harsh chemicals as they may damage the leather - look trim or the mesh lining. Store the harness in a cool, dry place when not in use. Check the buckle regularly to ensure it's working properly and that there are no signs of wear and tear. If you notice any issues, it's best to replace the harness to keep your dog safe.