change user name and password

[phangcs]

I bought a second hand MacBook. I want to change the "user name" and the "password" set up by the previous owner. I don't have the previous owner's password. How can I do this without re-formating the HD?

 

[SuperSnake2012]

Can you log into any administrator account to make a new one? If not, have you contacted the seller for the password? If they won't give it to you, I think formatting might be your only choice.

 

[Sigur]

I bought a second hand MacBook. I want to change the "user name" and the "password" set up by the previous owner. I don't have the previous owner's password. How can I do this without re-formating the HD?

Did he sell you a OS? Then I would say you just reinstall it. Or is there any data on the HD you need?