It appears you can’t replace an existing component on the Mac using SketchUp 2016. Try this:
- Create a 3 dimensional box.
- Use Make Component to create a component called Box.
- Then Explode the box.
- Use Push/Pull to enlarge (or shrink) the box.
- Use Make Component to create a component called Box (I have the Replace box checked).
- When the message stating a component already exists comes up choose Replace.
- Notice the primitives are not replaced with the new box nor has the box component in the library been updated.
This works on the PC version and also works on Mac version SketchUp 2015. Am I missing something very basic?