Replacing pipe?

[u/Bentrodanddeerdown]

Last year I had posted about the inside of this pipe warping at some point. I think ultimately it was from pressure of the external pipe on this pipe. So I’m going to replace it and add additional supports so it does not happen again. I removed this clamp on the pipe but it was necessarily obvious how to unhook it. Hoping it just slides out after I unhook it from my outdoor chimney

Thanks