Firstly, set a date 2 to 4 weeks in the future to quit. Then get rid of all smokables and smoking accessories in the house. Do not fall into the mental trap of "just this one pack". When you are craving a smoke, chew gum. Avoid any reference to smoking. You also should pick up a hobby that makes you busy.
Make a mantra
Here are some sample ones:
If you are feeling anxious, try to use these anxiety management exercises.
If these still do not work, get an unscented nicotine vape. However, do this as a last resort, and do the previous activities to the best of your abilities. If you do the vape, you will also need to wean yourself off the vape.