Wrap towels, cloths or a heating pad around the frozen pipe if you can reach it.
Turn on all the hot water taps in the house. As the hot water heats the pipes, it also will warm the neighboring pipes, helping the toilet pipe warm.
Pour warm water into the toilet. Continue adding more and more warm water into the toilet. As the ice starts to melt, you can add hot water. Adding hot water too soon to a frozen system can cause the porcelain to crack. Wait until you see the water level start to drop slightly and then add hot water to the bowl.
Continue adding hot water to the toilet until it is cleared completely. Remove the heating pad.