Rename
Navigate to the Company level Resource Planning tool.
Click Assignments and select Gantt (Beta).
Double click the category or subcategory name.
Enter the new name. Then click anywhere on the screen to save.
TipClick the undo 
icon to undo an action. Click the redo 
icon redo a previously undone action.
Click the undo icon to undo an action. Click the redo icon redo a previously undone action.