I think the best way to quit smoking is to reverse the process. You didn’t just start smoking 50 ciggs a day it took 20 years to build up to that many so does it really matter if it takes 6 months to stop?
Take small steps to ramp down.
Become conscientious of where you bring your ciggs and start eliminating them, one by one over time. Short trips to the store, leave the ciggs at home, on the computer checking emails, ebay no ciggs, you get the idea.
Don’t try an eliminate too many places at once, pick a couple and just work on those, once those become the norm eliminate some more.
Hang in there!