You can remove objects by deleting them from the document.
Or
When you delete objects, they are moved to the DesignEditor's Trash Layer.
See Also
Arranging Objects
Removing Objects without Moving Them to the Trash Layer
Restoring Objects from the Trash Layer
Removing Objects from the Trash Layer
Resizing Objects
Moving Objects
Rotating, Shearing, and Mirroring Objects
Duplicating Objects
Working with Auto Serialization
Grouping Objects
Compounding Objects
Masking Objects
Locking Objects
Changing Object Order
Aligning Objects
Distributing Objects
Spacing Objects
Nesting Objects
True Shape Nesting
Snapping Objects
Clear Transform