Step 1: Get FC seats (you don't even need the tracks).
Step 2: Take out old seats, remove tracks.
Step 3: Install SA/FB tracks on FC seats.
Step 4: Re-install.
Step 5: Profit!
This is only for manual tracks, I don't know if power tracks will work.
I've actually had the FC seats in my FB for 2 months now, but one of the 3 bolts holding the driver's seat in came loose, so I took it out to inspect (using FC tracks the passenger seat bolts right in and the driver only works on 3/4, the front inside bolt doesn't line up). I still have my original seats, so a little curiosity netted me the realization that the lower and lighter FB tracks bolt right onto the FC seats. Problem solved!
