Remove admin account A colleague of mine just got his new MacBook Pro and he ran through the set-up process. But as it turns out, he got the wrong MacBook Pro, so now, he needs to completely erase the already present data and account...

How can he completely erase all the data including the admin account? He already tried to boot from the recovery disk and to boot with Command-R. But all he gets is the new set-up assistant. He wants the MacBook Pro in its original state, so that when you open it you see the initial setup steps, and not the account he just created.
He could format THEN REINSTALL the OS and power off before the initial setup. 

Also there is a way to force setup assistant to run without reinstalling the system (some unix knowledge required and yes, this works in Lion):

Boot to single user mode

mount -uw
rm -rf /Library/Preferences/
rm -rf /Users/username
rm /var/db/dslocal/nodes/Default/users/username.plist
rm -rf /var/db/.AppleSetupDone
exit


(Note: replace username with whatever account short name you’ve created)