Brick chimneys all come apart the same way, brick by brick from the top down.

The only thing you can do is start the work.

If there are questions about what is actually behind the kitchen wall, start demo there to only expose the chimney.

When you have a better idea of what you are taking down, start at the top removing bricks.

It is a real PITA job to pop them loose one by one get them down to the ground above the roof, and even worse inside since you need to carry the bricks out of the house instead of throwing them on the ground.

Remember mortar is weakest in tension, so use you chisel and hammer to put the joints under tension and lift the brick loose.

Thanks---the sticky part is that this actually isn't a brick chimney, as far as we know. I've found a bunch of great references for removing those, but we've seen no evidence of bricks, and I imagine there would likely be some at the base or some at the top if there were bricks in the middle? Our fireplace chimney is brick, but there the bricks are very clearly visible in both the basement and above the roof line. In contrast, the kitchen chimney has a large metal belly in the basement and then a small metal cap where it comes out the roof.

Any thoughts on what might be in between the two? (I know, the answer is probably to give the plaster a whack or two---we're just hoping to figure out as much as possible before we take that plunge, since then we pretty much have to keep going!)

If it is a clay flue liner surrounded in plaster, it is probably going to come down easier than brick. Of course, if you have ever pulled anything plaster down, you know it is going to make a huge mess.

A clay liner basically just stacks together. One end is male and the other female and they fit over each other. They probably aren't going to come apart easily if they have 100 years of soot built up. They usually are in 2 foot sections, so it shouldn't be quite as tedious as taking down bricks.

The link below has a diagram of what might be awaiting you.

Here is a link that might be useful: diagram