Step 1: With a Finder window open, click on the Library folder that’s in your home directory.
Step 2: Drag it onto your desktop.
Step 3: Make it log off or reboot the iBook in question.
The end result: all of your preferences, your keychain of logins, your Safari bookmarks, your entire world has vanished.
The fix: put Library back in your home directory, not on your desktop, after you’ve logged off to make sure already-opened files don’t make you actually lose everything. We accomplished this by making an SSH connection from another computer. Another fix could be logging in as another user and opening up an Applications->Utilities->Terminal window and doing it manually.
I don’t know if there’s an elegant way to recover from this startlingly crippling little step.
Oh, I forgot: Step 0: Do all of these steps as a four year-old boy. Patrick Kehoe, über-hacker.