Well, first you need to really want it. Then get some medication to help you with that. I got something based on cytisine, because I specifically didn’t want a medication with nicotine, but what do I know, it was just my gut feeling.

After 25 days of using it I stopped smoking successfully. I first tried without any medication and let me tell you, the difference is huge, with the medication I had no physical withdrawal symptoms. The hardest part was breaking the habit, my brain was used to getting a cigarette on so many different occasions. But without the physical withdrawal symptoms, it was manageable (and ties to my very first sentence here - you need to really want to stop).

So yeah, get some medication and prepare to struggle for the first few weeks, because you’re used to smoking and your brain needs its routine. It won’t stop afterwards, it just gets easier with time. Currently on year 3 of no smoking and occasionally I still get the urge to smoke a cigarette. And from what other ex-smokers told me, that doesn’t go away even after 15 years, the brain is just weird like that. At first I got the irrational urge like few times a month, now I’m on ~6 times a year.

Best of luck!