I've just replaced a broken seat release handle on my wife's 2006 Fiesta and thank the people who've posted advice above.
I suggest that to reduce the probability of the release handle(s) breaking again try replacing the springs on the two release latches (at the bottom rear of the seat) with lower tension springs. I found lower tension springs at the local hardware store which cost $3.00 each; they were easy to swap and now the release handles require much less force to release the seat back and feel much less likely to break.
Hope this helps.