Using these Hawk HPS brake pads is straightforward. Just follow the standard procedure for replacing brake pads on your Subaru WRX with AP Racing CP8350 Caliper. Make sure to clean the caliper and other related parts before installation. As for precautions, avoid harsh braking right after installation to allow the pads to bed in properly. During normal use, be aware that the increased stopping power means you may need to adjust your braking habits. For maintenance, regularly check the brake pads for wear. If you notice excessive dust, you can clean the wheels more frequently. Also, keep an eye on the brake fluid level as the new pads may affect it slightly. These pads are built to last, but with proper care, you'll get the most out of them and enjoy a safe and smooth driving experience.