Changing the App Icon after the Mac App is for sale

Question

I develop Mac Apps. I have one for sale, and I am about to release an update for it. I would like to change the App's Icon to a slightly better one, but it seems that this is impossible.

Can someone please tell me if this is so, or if it is possible, tell me how to do it?

Any ideas, Thanks!

Answer 1

I think the answer is, you can't.