Generation 2 AirPods

I’ve had these for almost 2 years now. Bought pros recently so I don’t have a use for these anymore. Clearly we’re clearly loved and got a tone of use. I cleaned the AirPods and the case as best as I possibly can. The back on the case is stained somehow and it won’t come off. Aside from the look of them they still work perfectly. And if you purchase I’ll include a lilac purple case to go with it