How can I replace my AirPods case?

Click the following link to start a service request and purchase a replacement ➜ AirPods Replacement, Repair & Service - Apple Support

You can get an estimated cost, by scrolling down and using the Estimate calculator there.

This is a support community. If you have inquiries for returning a damaged or broken device within the coverage, contact AirPods Support - Official Apple Support

I hope this helps!