A loose toilet seat is annoying. Fixing a toilet seat usually results in replacing the seat. Hinges that have come apart or are missing screws where they connect to the lid or toilet are not replaceable due to the thickness of the seat. If the seat is merely loose on the toilet, an adjustment to the fastener will resolve the problem. Replacing the toilet seat is a matter of removing the same fasteners you adjust to make the seat tighter to the toilet bowl. Replacement toilet seats are available at home improvement centres.
Inspect the seat hinge to see where it is loose. Raise the lid and seat and inspect the screws securing the hinge. If the screws are missing or loose, you will have to replace the seat.
Pry up the caps of the toilet hinges where they connect to the top of the toilet bowl with a flathead screwdriver, revealing the securing bolts. If the seat is just loose, tightening these bolts will resolve the problem. To tighten, hold the head of the bolt with a flathead screwdriver and tighten the securing nut below the toilet bowl with a wrench.
Remove the attaching bolts, if the seat requires replacement. Hold the bolt head with the flathead screwdriver and turn the securing nut counterclockwise with a wrench. Pull the toilet seat off the toilet bowl.
Place the new toilet seat onto the toilet bowl and pry open the hinge caps. Insert the two securing bolts through the hinges and through the toilet bowl flange.
Thread the securing nuts over the bolt threads under the toilet bowl flange until they are hand tight. Tighten the nuts another full turn with a wrench. Close the caps on both hinges to complete the installation.