If you want a new toilet seat, it is a fairly simple way for you to do it yourself. Most toilets are set up the exact same way, so getting a replacement is very simple. You should be able to pick one up at any hardware store. There should be two bolts to remove to get the seat loose. If you are uncomfortable touching it with your bare hands, you might want to wear some disposable gloves.
The only thing that you need to pay attention to is that the seat matches the one that was removed. Some seats are elongated, and they would need to be replaced with the same type of seat.
Be careful not to overtighten the seat when you attach the new seat since this could crack the porcelain seat. If that happens, there is no way of repairing it, you would need to replace the entire toilet seat.