Match it to the existing siding on the rest of the house. Please find out how the existing chimney was constructed, some used flue tile with brick, etc

and some used liner with wood frame surround and brick exterior.

If there is a wood frame the brick can be easily removed and replaced or you can use other materials to replace it.

If no wood frame and clay or flue tile were used and you try to remove the brick you will need to reconstruct the entire chimeney.

That said, depends on the shape of it, some acid clean the brick and repoint it, some plaster over it and use a stucco finish, and some resurface the brick using other materials, like siding, cultural stone, etc.

If no wood frame and clay or flue tile were used is what we have. Three liners in one chimney. We want to recover/make it solid/keep the bats out. If the bricks are crumbling can we just resurface?

That is my ask, once we take it down what's a less expensive, safe, durable way to not use brick?

We paid $750, in 2018, to have our chimney taken down and rebuilt. I thought that was very reasonable at the time. YMMV

If we could find a mason. it will be about 8 thousand dollars. But that isn't possible this year I hear.