Using these Cusco exhaust hangers is easy. Just remove the old factory hanger and replace it with this new one. It's a direct fit for your 2002 - 2007 Subaru WRX or STI. When installing, make sure it's firmly in place to get the best performance. As for maintenance, you don't need to do much. Periodically check to see if the hanger is still in good condition and there's no excessive wear or tear. If you notice any issues, it's best to replace the hanger right away. Also, keep in mind that these hangers are sold individually, so you can buy as many as you need according to your situation.