Toilet seats are fairly straightforward things to refit if they have become loose, or to replace with a new one if they have become damaged or the fixing points are broken. Most WC seats fix to the toilet bowl itself by means of a pair of hinged brackets.
With the seat in the vertical position, you should be able to see the two hinge points. 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 will be fixed to the toilet seat itself.
Re securing a toilet seat is usually a simple matter of tightening the retaining fixings. Lift the hinge cover pieces if there are any – you may need to gently prise them up with a flat-bladed screwdriver. 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. To tighten, 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. In this case, tightening or loosening of the fitting will be done by turning the nut on the underside only. The nut on the underside may require a spanner, or it may be a winged nut that can be turned by hand.
Undoing the Toilet Seat
Lift the hinge covers if there are any, and you will see one end of the fixing bolts which may be 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. This nut may be plastic or metal depending and will have a plastic washer to protect the bowl from damage.
Remove the Seat
With the fixings undone, the seat simply lifts up and the fixing bolts pull through the holes in the back of the bowl.
Fitting a New Toilet Seat
New toilet seats may have the hinge brackets already attached or, they may be loose in the packaging. They may be screw fixed to the seat or may simply slide into a slot. With the hinge brackets secured to the seat (or simply slotted in) pass the bolts through the fixing 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.