The Power of Habit says it's impossible to

remove

a habit. You will need to combat it with willpower. This may become habitual itself. But when you suddenly have a really bad period, chances are big you will fall back into the old habit.

The book goes on to say that it is possible to

replace

a habit. You need to keep the trigger and reward the same, but replace the routine.

You could replace a smoking habit by one below, depending on your trigger and reward at the time.

Trigger

Routine

Reward

Context

feeling stressed

grab jacket

invite colleague

go outside

light a cigarette

feeling connected /

relaxed feeling

Smoking

feeling stressed

grab a jacket

invite colleague

go outside

run

feeling connected /

relaxed feeling

Running

feeling stressed

find a quiet room

meditate

relaxed feeling

Meditation

Same with drinking a lot of coffee.

Trigger

Routine

Reward

Context

feeling tired

walk to kitchen

make coffee

pour a cup

add lots of sugar

drink coffee

caffeine /

sugar /

hot beverage /

5 min meditation

Coffee

feeling tired

walk to kichen

grab apple

eat apple

caffeine /

sugar /

hot beverage /

5 min meditation

Fruit

feeling tired

walk to kichen

make tea

add lots of sugar

drink tea

caffeine /

sugar /

hot beverage /

5 min meditation

Herbal tea

The most difficult part here is finding out exactly which trigger and which rewards drives the behaviour.

You can have a desire for coffee because:

you're tired -> caffeine

you need a break -> 5 min break

you have low blood sugar -> sugar

your stomach is upset -> hot beverage

So once you know which trigger and which reward are driving the habit (in this case) you can replace the routine, but keeping the trigger and reward the same.

(src: Book: The Power of Habit)