Press the Xbox button of the controller to go to the dashboard. Navigate to My games & apps and select the item (app or game) you would like to uninstall. Press the Menu button of the controller and select Uninstall. Follow the onscreen instructions to delete the selected item.
Xbox One users have the ability to expand the storage capacity of their console with external hard drives. For more information, please read our article on How to Extend the Storage Capacity of the Xbox One.