I had the same problem with a used machine. In fact, when I called the lady who sold me the machine, she told me that the owner was a heavy smoker...she was selling the machine for the lady's husband, because the owner died from lung cancer. So sad.....I used a soft cloth with febreeze on it. Set it in the garage for a few days, used febreeze again, I got rid of the plastic bags that they sent with the extra feet, threw away all the thread she sent, and cut all the thread from the bobbins.....anything that would hold an odor. BTW Plastic does absorb odors. I put the machine box in the attic after I light sprayed it with the Febreeze. I wiped down every inch of the machine and all of the feet...everything.
I was surprised at the nicotine that was wiped off the machine, I could see it on the clean cloth. It worked on my machine hope you get rid of your smell too.