How do you defrost an airplane?

Ice build-up is a common problem at airplanes. To remove the ice when you are on groun you call the airport's de-ice truck that sprays the aiplane with antiicing liquid.

If you look at the leading edges of most wings (and large props), you'll see black strips called 'de-ice boots'. These are rubber sleeves that are inflated to change shape of the wings and break ice off as it forms. On modern aircraft, the system is activated when icing conditions are suspect (descending through cloud, etc) and inflates/deflates them one at a time until switched off.