Take the seat out of the car.Remove the reclining knob, remove the plastic covers on either side that go over where the backrest joins the lower by pushing out the 3 plastic rivet typr thing from behind. With the covers off remove the clips that hold the backrest to the lower , you can now take the backrest of the base . Look down between the central part of the seat base and the side bolster and you,ll see some hooks pressed into the seat base frame.Prize these up to release the wire that uns through the bolster material. Turn the base over and unclip the material from the base frame.Remove the black plastic boss that the tilt mechanism locks onto and you can now take the material off.You may need to slide the front slidy bit right out of the way on the seat base .To do this turn the seat over and remove the big R clips that retain it.

Sorry if this is a bit hard to follow but i,ve been typing this with my 4 year old hassling me . Any probs PM me and i,ll give you my mobile number