There's nothing scary in there, kevs.
"Reset Password" is mentioned
only because Apple, for some obscure reason, buried the reset home folder permissions functionality under that tab.
Just follow the instructions:
In OS X 10.6 Snow Leopard, boot to the Mac’s install disc by inserting the disc and holding down the “C†key at startup (or holding Alt/Option and selecting the disc from the boot menu). Once you’ve selected your language and are at the installer’s main menu, choose “Utilities†from the menu bar, then “Reset Password.†This menu allows you to reset user account passwords but also allows you to reset ACLs by choosing a user account from the top menu and then clicking “Reset†at the bottom of the screen.)
And as for your "unknown user" and why you can't delete the file, judging from your prior posts I'll guess that your intern did something weird.
Edit: As I said, hope springs eternal.
