Hey guys. I have 2011 mbp and i'm trying to sell it online...but i realized that i need to delete my main login account before selling it? I had to preinstall stuff but..not sure how i would delete it so that the buyer can make his main login account? For example: I reinstalled the osx and it asked me to make my password account. So in order to install some programs, I had to make my account. Any help?