You won't replace the "data" folder (where data is stored).
Are you saying if i copy the "data" folder of the upgrade version over the installed "data" folder it will NOT overwrite the existing data? This doesn't make sense to me.
When you ask us to read the documentation, we do, but we know that not all documentation is written clearly, nor can we assume it is accurate. My experience is there are plenty of gotchas in most online documentation.