1. Hold down Shift and drag one shape that is already on the drawing canvas over another shape.
2. Drop the shape when the underlying shape outline is highlighted purple to swap them.

Related

• Overlap shapes and containers - Hold Alt on Windows or Option on MacOS.
• Group and ungroup shapes via the right-click context menu.
• Replace an existing shape - drag a new shape from the library and drop it on the existing shape when you see the replace icon.
• Duplicate a shape on the drawing canvas - Select the shape then press Ctrl+C followed by Ctrl+V to paste a copy.