lifetime warranty claim

[Chay Siu Ang]

I bought a Ameriware Professional nonstick pan many years ago from Costco. I remember I bought it for $99.00 for one pan, which is quite expensive at that time. I bought it because I was told that it is lifetime warranty. But not long later the nonstick surface has peeled off and I don't know how to get a replacement. I did not throw it away because I keep remembering it is under warranty. Please tell me what to do.