Using this lower spray arm is easy. First, make sure your dishwasher is turned off and unplugged for safety. Then, remove the old spray arm from the upper basket of your Dishlex Global DX302, DX403, or Westinghouse SB907 dishwasher. Simply attach the new spray arm in the same place where the old one was. Once it's securely attached, plug in your dishwasher and turn it on. When using your dishwasher, load your dishes properly so that the spray arm can reach all the dishes for a thorough clean. As for maintenance, it's a good idea to check the spray arm regularly for any signs of wear or blockages. If you notice any food particles or debris in the nozzles, gently clean them with a small brush. If you ever have any questions about this part or its compatibility, don't hesitate to contact us.