I wish you and your friend all the best. There is
nothing good about smoking. If it's any consolation, the wife of a friend of mine -- she's about the same age as your friend -- was given an almost identical diagnosis 18 months ago. Of course, she smoked like a furnace until the diagnosis. Radiation, chemo, and a significant bout with neuropathy (sp?) causing her to be unable to walk unassisted for months. Not pleasant at all, but she beat it. No sign of cancer; and the effects of the treatments are receding -- she can now walk without a walker or cane, and can drive again. An almost full recovery of motor skills is considered likely. Best of all (according to her), she's now smoke free. She says it was almost worth it (which I don't believe for a second, but which gives you an idea of how powerful the addiction is).
I won't be a great deal of help with quitting tips. I last smoked cigarettes in grad school (that's when you're supposed to be smart, right?) twenty years ago; my peak consumption was about ¾ of a pack of ultra-lights (Barclays) a day, and even at that modest level, quitting wasn't easy. I can only imagine how difficult it must be to rid oneself of a heavier habit. My modest tip, for what it's worth: apples. Two or three Granny Smiths a day were a big help to me. Why apples? Well, they give your mouth something to do; they're a low-cal solution to the return of your appetite (food will taste better); and they have fiber (too much information, perhaps, but cigarettes have a laxative effect, and if your body has acclimated itself to them, giving them up can result in constipation). Lots of water, and lots of walking, too. Good luck!
Apples are a great way to help with beating tobacco. I recall chomping apples, pears, etc and this helped me a lot.
I had previously reduced the nicotine content in the cigarettes I was buying (went from red Winstons to gold Light Winstons to white pack Ultra Light Winstons) but this resulted in buying more packs. When you're hooked, you're hooked. There are no half-way measures to get unhooked.