Cold turkey, bruv. Remember, you are not addicted to anything, you were a non-smoker before you became a smoker, so you've done it before. The habitual side of 'going out for a smoke,' 'relaxing with a smoke after dinner or sex,' or 'smoking while writing that blog post' is the only issue that you may face. If you break these key timings (have a nap or brush your teeth / rinse or drink a glass of col water instead), you have it in the bag. I smoked a pack a day for 10 years and nearly 2 packs a day for the last 4 months before I quit. I went from almost 40 smokes per day to 0, in one day. Was it hell? Actually, no, not really. I smell good, I look better, and I am looking forward to a longer life and not dying of a collapsed lung and cancer (I hope).
Good luck!