Fixing it was easy...less than an hour's work. My 04 ext cab doesn't have the torx bolts that hold the seats down, just regular hex bolts. As such, they were easy to remove by using my air ratchet. Slide the seat all the way back to remove the front two bolts, then slide the seat all the way forward to get the rear two bolts out. Just have to remove the plastic shield that goes around the bottom of the two rear chair "legs": really easy, they just each have one single christmas tree type reusable fastener.
Once the bolts are out, lean the seat back and disconnect the plug under the seat. This plug is the for the sensor that detects when a child is seated in the passenger seat and therefore needs the airbag turned off.
Remove the seat from the truck and flip it upside down. Move the seat lever and start watching the motion of the parts on the driver's side of the seat (the side that has the lever). Then look at the other side (the passenger side). You'll likely find that the brown plastic collar that keeps the cable onto the frame has popped out. It's the same design as a brake cable on a bicycle. Which ever side has popped out, remove the plastic seat moulding that runs the full length of the seat to get easier access to the parts. Just a couple screws plus the phillips screw that holds the lever on. Plus there's a clip too, which you can easily pop out.
Simple to pop the brown plastic collar part of the cable back on to the mounting "fork", but you might find that the seat foam puts pressure on the cable which is what caused the cable to pop out of the mounting fork in the first place. So here's what I did to prevent this from happening again: I took a razor blade and cut away some of the foam so that the cable wasn't being pushed by it anymore. Once you push the cable back into the mounting bracket (fork), put everything back together. That should do it.