Owncloud - upgrade higher than the normal 513 mb with terminal in Mac

Hallo! I´ve intalled on my QNAP “Owncloud” and it works.
I can watch datas from everywhere. But I want to change the data from 513 mb.
I can´t put a Movie in the own cloud.

So I want to change it with the Terminal in Mac. Can you explain Step by Step

Thanks a lot

Hey, i found the following documentation in the past:


However it seems to me that there are too much configuration options / possibilities to give a step by step guide.