The end has come and gone, and the survivors of humanity have adopted a new religion - dismantling the sins of the past. Dismantling the cities, roads, towns and relics of the past by hand. The resources being returned to nature as best they can.
With no industrialised technology, how much work would it be to dismantle a city? Assume that the results are being taken away by canal barge for disposal.
Bonus points for suggesting things to do with a skyscraper of glass, or tonnes of tarmac that fit the atonement philosophy.
Assume knowledge of up to steam tech... But no desire to use it.