Replacing a toilet seat is a task that may be unfamiliar, as it is not something that you do frequently. If you have ever wondered how a toilet seat is secured to the toilet, it is done by two screws that are threaded through two holes in the toilet. There are two different scenarios when it comes to toilet seat screws, and the design of your toilet can help determine how difficult this task can be.
Examine the area where the hinges on your toilet seat meet the toilet itself. If there is no small tab to lift on the back of the hinge then you have toilet screws with no head on them. The screws are installed directly into the hinge itself. Reach under the toilet and you should be able to feel the screws. Reach up the screw and you should be able to feel the nut that is holding it in place.
Spray lubricant such as WD-40 on the nut regardless of whether it is plastic or metal.
Use a socket wrench with a socket deep enough to cover the entire screw in order to get to a metal nut. Loosen the nut carefully before trying to remove it. Once the nut is loose, you can remove it completely with the socket.
Use vice grips to remove the nut if it is plastic. Be very careful not to twist the grips too hard and start ruining the nut. Grip the nut very carefully, and slowly start to turn it. With plastic nuts you should hear a pop when it has been loosened, and at that point you can remove it.
Remove the other nut in the same fashion as the first one.
Analyse the area where the toilet seat hinges meet the toilet itself. If you see tabs that can be lifted on the back of the hinges then there are screw heads you can access for your toilet screws. Flip up the tabs and make sure that the screw heads are square and held in place by the hinge assembly.
Spray a lubricant such as WD-40 on the nuts under the toilet to help loosen them up.
If your screw heads are square then simply use vice grips to reach under the toilet and loosen the nut. If the screw heads are round, then place the screwdriver in the screw head to hold it in place as you loosen the nut.
Lift the screw head high enough where you can unscrew it with the screwdriver. Hole the nut in place with the vice grips and then remove the toilet screw.
Repeat the process for the other screw.
If it has been a while since the toilet seat has been changed, then you may want to clean the screws with white spirit before you get started.