Chimney on Long Caboose

[BobHuddleston]

I have a problem: my D&RGW 1:20.3 LS Long Caboose has a problem: the stove smoke stack is too high to go through my tunnel and needs to be shortened. I pulled the roof off and cannot tell if the two pieces of the chimney (parts 00Z01 and 0AB07) are glued or simply a very tight fit. I don't want to break them but how are they removed?