No problem, I'm a dummy too ;-)
Florian showed me how to do it. I have no idea how it works on a MAC, but after installing SubVersion on Windows you have on right click into a folder something like "SVN checkout" popping up.
Click that and you can enter the url of the SVN link and start the checkout process.
That's all... and this is how it works for me.
Hopefully you can fill the gaps between Windows and Mac yourselves. Or someone else can help!?