Stetson hats are steam blocked and given a special coating of shellac on the brims while at the Stetson factory. You can, however, reshape a felt hat at home using steam and/or hot water. Which method to try depends on the severity of the creasing. For assured success with shaping a Stetson hat, check for a local haberdasher before you attempt to steam mold a valuable hat. Special hat shaping tools and service are often available at one of these fashion shops for men. There is an old cowboy adage that your hat ought to always be set down upside down in order to catch all the good fortune, so get your hat in shape and keep good luck always in your Stetson.
Bring water to a boil in a tea kettle, and place the dented areas of the hat right into the stream of steam escaping form the spout.
Hold in the steam for a few minutes until you see the felt start to soften and change shape, ever so slightly. Move the hat back and forth to feather the steam into the fabric.
Form the hat to the desired shape with your hands.
Allow the hat to dry. Spray with a hat stiffening product.