I don’t smoke but my wife smoked heavily in the early years of our marriage.
She wanted a pet rabbit and I said that we couldn’t afford one.
If she stopped smoking could she?
Ah but if you start again what do we do with the rabbit?
In her late twenties, having smoked since she was 18; she finished the pack that she had and hasn’t smoked since.
(I’m not telling her age but I’m 78.)
[Ed+ A voice in my ear is saying that she was a child bride

]
So:
Be clear - no more smoking of anything.
Have a motivation. If not a pet rabbit, a gymnastics target or a distance to run run, a peak to bag.
For the first few months try and avoid places where you can smoke or be offered a cigarette. That was hard as in those days people smoked at their desks.
Don’t try and taper off. Just do it and suffer for a while.
(fyi. This isn’t my list.)