The majority of toilet seats are attached to the toilet bowl itself by means of a pair of brackets with hinges. These may have a cover piece over the pan fixing point so that the fixing is smooth and easily cleaned. One section of the hinge fixes to the pan and, the other fixes to the toilet seat itself. Chessington Plumbers are experienced in this area.Seat (loose).Lift up the covers on the hinges if there are any fitted. A Chessington Plumber carries the correct tools. The fixing bolts may have a screw head. If so, reach round to the underside of the fixing and hold the nut in position underneath while you slacken this screw head slightly. With it loosened, you can now make sure the seat lines up squarely with the bowl before tightening fully again. Hold the nut underneath and use a screwdriver to do up the screw head from the top. If the bolt has no screw head, it will be shaped so that it is held in position in the upper fixing plate. Or, you may have an upper plate with an integrated bolt. Undoing the Toilet Seat.Again, lift up the covers on the hinges, and you will see one end of the fixing bolts which could made from plastic or metal. If this has a screw head, you can undo it from here. Reach round to the other end of the bolt and hold the retaining nut in place while you unscrew the bolt. If there is no screw head, you can simply undo the retaining nut underneath. The seat should loft away.Fitting a New Toilet Seat.With these hinged brackets securely fixed to the toilet seat, put the bolts through the securing points remembering to add the upper side washer arrangement first. Mount the underside washers and nuts and tighten so that the seat is roughly held. As before, this may be done by tightening the upper screw heads if there are any, or by tightening the nut underneath. Align the seat so that it opens and closes to the right position. There is usually some play in the fixing points allowing this to be done. Once the seat is correctly aligned, finish tightening the nuts. These only need to be hand tight. Over tightening may damage the seat or bowl.