I'm all new to this. How do I modify the thickness of a cylinder? And how do I make slight alterations to a 3D object in general?

You could try using the Move Face command.Changes to a 3D object can be made with any of the 3D Solid Editing commands such as...UnionSubtractIntersectSliceImprintMove FacesExtrude FacesTaper, Copy, Offset, Delete, etc. FacesExtract or Copy EdgesJust to name a few.
John Connor2018-08-14 18:22:01