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You can display the Boolean & Facet toolbar by right-clicking in any toolbar area and selecting Boolean & Facet.
These tools are also available on the fly-out toolbar from the Drawing Tools. 
When Boolean operations are completed, you can edit the shape and location of the objects used to create them. See Editing 3D Objects using Selection Info.
If you plan to assign materials to your 3D objects, it is recommended to do this after the Boolean operations are performed.
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