Optimizing a scene, Part 2. Shapes, Instances and the Replace Selected Function

In part two, we look at a component of the large and complex scene that needs to be optimized. We replace duplicated objects with instances and look at specific conditions to watch out for.

Part 1 is here (Replace/Exchange Selected).
Part 2 is here (Replace/Exchange Selected on a more complex scene).
Part 3 is here (Snap To Tool).
Part 4 is here (creating piping segments).