The installer said to expect him between 8am and 9am. He arrived shortly after 8 and finished the job by 11.15am – just over 3 hours. And to a professional standard. Mind boggling.
He offloaded the new chimney components and I noted all were new out of unopened boxes and bore UL compliance labels.

He began first with removing exterior wood siding from the chimney and then the 7/16 OSB (oriented strandboard).

With the OSB sheathing removed the rear of the fireplace is visible.

He loosened and extracted some of the flue through this opening and then climbed to the top of the chimney to remove the chimney cover and cap and the rest of the flue.

He had an assistant who received and passed him pieces as needed. Next he and his assistant pulled out the old fireplace.

He installed the new flue and a new chimney cover and cap – here are the latter two items awaiting installation.

Then he and his assistant brought in the new hearth pad and sited the wood stove on the hearth pad and connected the stovepipe so it went through the wall to the new flue.

And all of this done in just around 3 hours. I fixed plywood sheathing to the chimney exterior and the room interior and over the next week I will repair the chimney exterior and install a tile surround behind the wood stove.
My neighbor asked if he could have the old fireplace and flue which I set aside for him.

And last night I lit the wood stove and marveled how long it took to consume my oak logs and the radiant heat it provided. I should mention, in conclusion, that a good reference for me was “The Woodburner’s Companion” by Dirk Thomas.