You may easily rename your classes, methods and even local variables with automatical correction of all places where they are used at.
To try it, position the editor caret at the name of any variable and press Shift-F6 (Rename...). Type the new name in the appeared dialog and press Enter. You may browse all places where the variable is used at and then press the "Do Rename" button (Alt-D) to finish the renaming operation.