Doing a little exploration for a buddy's buddy. He has a wood stove with 6in. liner. There is insulation the length of the chimney that is NOT solid, but not loose. When the guy bought the house, an inspector said the liner was beginning to rust out and needed to be replaced. How do you replace a liner with insulation the length of the chimney? Do you run a 5.5 or a 5 in. liner down the exsisting liner? Or, is there a way to get the liner out with the insulation? Or, must all the insulation be taken out? Never saw any of this set up. I am going on what they are telling me. As always, thanks.