You can rename a class or an interface by modifying its declaration in the compilation unit in which it is declared. However, if you also want to update all references to it, do one of the following:
Creating a new Java class
Creating a nested interface
Creating a top-level interface
Creating a top-level class
Creating a nested class
Creating a class in an existing compilation unit
Package Explorer
Refactoring actions
Refactoring dialogs
Refactoring preferences