We had same problem here on a mac mini. First only removed the usb related kexts from /Library/Extensions:
nxusb_helper.kext, nxusb_io1.kext and nxusb_io2.kext.
Then removed kexts from /System/Library/Extensions/
nxaudio.kext, nxfs.kext and nxtun.kext
And from /Library/LaunchDaemons/
Then it worked.
A hint: when starting with command-R, start a terminal from utilities on the menu bar,
the actual root dir was below /Volumes/Macintosh HD/