1. I am selling a unibody MB 2. I understand how to use utility to write 0's on the hard drive. 3. What instructions do i give the potential buyer, so that when they turn on the MB, it is like a new computer? Do I just tell them to insert the current OS X dvd into the drive, and turn it on, or should I do that in advance? I assume they will want to set up their own user name, etc. ,so I am looking at how they can get the computer ready for them.