I recently had my external chimney lined in prep for putting a wood stove back in. After the guy left, I find that the bottom cap seems to be screwed to the tee and the outside clean out door has been sealed shut with something. I can't figure out how we are supposed to clean our liner now except for renting a boom or scaffold every time to do it top down as the chimney is 8 feet above the very steep metal roof. Any advice?