I feel Carr’s The Easy Way to Stop Smoking is a reproduction of “The Will Power Method" with a little more gloss on it. One has to know the mental state of a smoker before you can even think of preaching them to stop. If they have the willpower, then a smoker can do anything, even cold turkey. If not, then nothing is going to help.
Coming to the book itself, I think it is atrociously written, and very patronizing and not up to the mark. One can go for many other books if they want help to quit smoking.