Here is the before picture!
First step was to remove the seat, and remove the staples under the seat to remove the fabric. Keep the original screws though, cause you'll need them later
Add thumbtacks to your seat on the back to make sure the original padding stays in place.
Now start pulling your fabric very tight along the back, start gluing ( uh-- that looks strange.. the word I mean) the fabric to the board
Now add your seat back to the frame and screw back in your screws. Remember? Told you that if you didn't keep your screws you'd be... screwed