I'm sorry I'm late to the party, but for future readers that may do something like this:
You can start your Mac in target disk mode by holding down the T key during bootup. Now you can just mount your broken computer as a hard disk to another computer, pull the important files and then restart while holding down Cmd-Opt-R to force internet recovery ( as long as your Mac is about 2011 or newer ). This will restore your mac to its factory OS and look.
It doesn't sound like he has access to another Mac, is on the road, and just needs emergency access to the files.
I didn't realize Finder > Trash mangled the permissions, though, I thought it only changed ownership. I need to experiment with this when I get my MacBook back from repair to see how badly it messes things up.
I got the same problem of placing the private files in the trash. The computer automatically changed its date/time and once I tried to log in once again it would not accept the passwords I entered, regardless of rewriting the password using shift+R.
However my computer does not have space enough to reinstall macOS. Ill try to use an external hard drive to install it and see if I can put back all files I intially placed in my trash.
Can anyone explain how exactly to fix this issue. I deleted a file in the private folder, and as the writer of this topic said, I can’t start my macbook.
When pressing command R I see the option to install mac os but I aint got enough space for this installation. I have no idea how it works with terminal or external discs, but I have an seagate 500 gb hard disc (in case something can be done with that). Any help is welcome. I have online classes again Thursday And some important files there which I would like to recover. Thank you.