How to manually install pgfornament in LaTeX Live 2015?

I need to manually install the pgfornament package into my 2015 TexLive installation, on Mac OS X (Snow Leopard, a very old version of the Mac OS). It’s the first time that I want to manually install something for LaTeX, so I feel very uneasy and don’t want to mess my installation. Of course, I’ve consulted the package documentation:

https://ctan.math.ca/tex-archive/macros/latex/contrib/tkz/pgfornament/doc/ornaments.pdf,

but it seems to be inconsistent in the installation section (especially on page 5). I’ve downloaded and unzipped the package, which gives a folder called pgfornament. I opened my 2015 TexLive folder (called "2015"), and I don’t see any "/texmf/tex/latex" folder in there, as requested in the package documentation.

So what should I do now?

(I could install the newest version of TexLive on my Mac, but I’m currently working on a big and messy document right now, and I don’t want to rework eveything if the latest TexLive changes something!)

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EDIT: I’ve found a solution there:

Installing ornaments