Using the AS3 front brake disc guard is easy. First, remove the front wheel spacer from your bike. Then, install the guard in its place. Make sure it's properly aligned and secured. When riding, this guard will protect your front brake disc from rocks and other debris. As for maintenance, simply clean it with a mild soap and water solution from time to time to keep it in good condition. Avoid using harsh chemicals as they might damage the plastic or the finish. Also, regularly check the mounting bracket and the guard for any signs of wear or damage. If you notice any issues, consider replacing the guard or the bracket as needed. Keep in mind that this guard is designed to work with 270mm oversize discs, so make sure your bike has the right size disc for it to function properly.