as said, the cover is clipped in on the rear lip of the seat, if you feel where the end of the cloth and the metal join, you can simply insert a small screwdriver into the gap and prise the cloth out

mine has a few screws hidden under the rear felt cover thats glued to the back of the seat back which i had to lift up to unhide them

i've got it somewhere in the garage so i'll get some pics over the weekend if you are still stuck