Reinstall os x as new mac

[Tomerco]

Hi there,
i just bought a new mac and my sister used its for the first time,
now it says "my sisters name" - mac.
i would like to know how to make a fresh install like i was the first to use it.
thanks

 

[Weaselboy]

Just do a command-r boot to the recovery system. Then start Disk Utility and erase Macintosh HD. Quit Disk Util then click install OS and wait while the 4.7GB installer downloads from Apple's servers. Once that is done and installed you will get the setup process just like a new machine.

 

[glenthompson]

After you do that, if she will be using your computer, create her a non-admin account for her to use.