As usual, by pressing
F2 on the package name, you can rename or change the package name, and also by right-clicking and then select
Rename option, you can change or rename the package name.
When you press F2, it will show you the dialog box as:
In this dialog, don't forget to check the "Update references" checkbox because by making "check" to this check-box, it will make changes to all the references of the package which are referred by other components of project.