I actually just went through this a couple months ago .
Shipped a bench seat out of my 72 duster to another member half the country away from me.
All I did was take the track off and stuffed it inside the underneath of the seat and ziptied it all in place.
I left the seat assembeled and just folded the seats forward.
Then I went to walmart and bought a bunch of boxes and box tape and cut and folded my own box to fit the seat in and then folded up and old tarp and stuffed in in the box in a few places for added cushion to protect the seat and then I tapped it all up.
Then I went to my local grey hound station and they shipped it for me for only $100.00 and it only took 3 days for it to ship!
Hope that helps