It seemed that quitting smoking would be impossible, but you turned it into something that was easily conquerable. That is why hypnosis has been so successful with changing habits for at least 300 years. Regardless of the method you choose the suggestions outlined below will make the process of becoming a nonsmoker significantly easier. The word 'try' implies failure. Let's pretend that your mind is a computer.
Computers are either on or off.
They either do a task or they do nothing. It is impossible for a computer to 'try' to do any job. Your human computer works the same way except that when you ask it to 'try' something it simply gets confused and does nothing. If you wish to be a nonsmoker you must stop trying, make up your mind to be a nonsmoker. Your mind is a biological computer and only acts on the thoughts YOU present to it.