Install usbnetwork, and log in to the device via ssh / copy the files there via scp.
See
https://wiki.mobileread.com/wiki/Kind...USB_Networking
In case you don't understand what this is all about, I strongly recommend not to do it. Rather, learn about Unix/Linux and its command-line tools first, then come back.
Don't blindly tamper around or try out things, because there is no safety net, and you'd almost certainly screw up somewhere -- up to the point of potentially bricking your device.