[hatzie]

It's nasty to get rid of the smoker smell and it still comes back at times.

A tub with Hydrogen peroxide hair salon developer and water mix in the sun will kill the smell in the hard plastic parts. Google Retrobrite.

Depending on how bad it is it may be easier to replace the heater box and ducts with used from a wreck.
You definitely want to wash everything under the carpet and behind the hard plastic beauty panels with an enzyme smoke killer. This includes the doors.
Pull off the plastic behind the door panels and replace it with fresh 100mil plastic that doesn't smell like tobacco smoke.

I usually shock a vehicle with ozone machines for 24hours on a hot day after I pull out the soft parts like seats, carpet, and headliner. I usually make sure the door cards are off as well.

Anything soft is pretty much done for.
ACC Carpet with Mass backing has fit well in all my projects. You'll never get the smell out of the old stuff.
The headliner is done. The backer will soak up tobacco smoke like nobody's business. Get a used one from a non-smoker wreck and re-cover it. I'd replace the dome light and overhead console at the same time... you may be able to salvage hard plastic bits of the overhead console with the above mentioned tub of H2O2 and water and then re-cover with headliner material. Depends on how far you want to go.

The seat covers are done for as well. New Leather is under $1000. Cloth can probably be had but it may be almost as expensive as good leather.

Seat foams can sometimes be cleaned enough to get rid of the smoke smell in a large laundromat machine but you'll need to run em for several HOT cycles with 1/4 cup of White Vinegar, 20 Mule Team Borax, and good Lye Laundry Soap. A good Enzyme smoke-killer biocide from one of those outfits that fixes burned homes will help as well.

If the Durofoam Drivers' butt foam is available from TheSeatShop get one. It made my 2005 driver seat feel better than new.

Wash those seat frames before you put the foam and upholstery back on.