making slumped items from wine bottles

Someone that I know had a slumped wine bottle that she bought to be used as a
bowl, or dish. I am really a potter, but thought I might like to try to make
one of these, but don't know a thing about it. My question is could someone
tell me of books I might buy, or give me a brief instruction on how to do this?
OR, even tell me of a web site that would be instructional. I have an electric
kiln that is computer controlled, so I can fire to any cone, and program as
necessary.
Thanks. Martha