How can I refinish an interior chimney pipe to make it appear rounded?
Where I live, there are two or three places that specialize in fireplaces, like a re-modeler's dream.  Find what you have locally and take a picture of your fireplace and your neighbors fireplace (before and after) and explain what it takes to change yours.  Then you will know what you need and whether it is something you want to handle as a DIY'er or pay to have done.  When you learn more you can search the whole world wide web. (I love saying that) to even help you take it to the next level.